As the sun rose on Monday, Jan. 1, 1900, Americans awoke to a new decade — the first in what would be called an “American Century.”

Things were changing. George M. Cohan was a hit on Broadway with classics like “The Yankee Doodle Boy” (1904) and “You’re a Grand Old Flag” (1906). W.E.B. Du Bois and his colleagues founded the Niagara Movement (1905) and the NAACP (1909) to advance civil rights.

Americans were on the move. Adventure-seekers were flocking to a new frontier — Alaska — in the latest “gold rush.” And in 1903, two inventors down at Kitty Hawk, N.C., proved humans could fly.

But for many, the new century wasn’t all that different from the previous one.

A Civil War veteran sat in the White House. Most roads were made of dirt and/or mud, depending on the season. Of the nation’s 45 states, those south of the Mason-Dixon Line were mostly poor, with meager industry and sharecroppers — many of them former enslaved people — working the land.

As of 1900, most Americans — 99% by some estimates — lacked indoor plumbing. This meant bringing water into the house in buckets from a well, stream or cistern. A rare warm bath was prepared by heating water on the stove, and many people tended to their other bathroom duties out of doors.

Yet the promise of America was drawing more immigrants than ever before — an annual average of nearly 900,000 people for the years 1900-1914, according to the Library of Congress.

Unlike previous generations of immigrants, most of the new arrivals came from Southern, Eastern and central Europe. Most were Jews or Catholics.

Immigrants were quickly put to work in the nation’s growing manufacturing centers and on its sprawling railroads, in eastern cities and the coal mines of the northeast. They worked long hours in grueling conditions, desperate for a chance to get ahead.

Many lived in cramped urban spaces — most famously, the Lower East Side of Manhattan, where getting water and completing bathroom tasks was a monstrous proposition for the 540,000 people living in a 1.5 square mile area.

After a lovely morning of sightseeing at Niagara Falls, a pleasant lunch with his wife and a good cigar, President William McKinley departed for a Sept. 6, 1901, reception at the Pan-American Exposition in Buffalo, N.Y.

Just 10 months earlier, the former Ohio Governor had easily won reelection, defeating oft-nominated Democrat William Jennings Bryan, Social Democrat Eugene Debs of Indiana and a pool of other candidates.

But that fateful day in Buffalo, anarchist Leon Czolgosz waited patiently for his turn to greet the 58-year-old president. As he approached, he raised a concealed revolver and shot the president in the abdomen. Eight days later, the president was dead.

Newspapers brought the tragic news to the nation. “An Anarchist’s Damnable Duty Done!” the Birmingham, Ala., Age-Herald declared in an alliterative front-page headline. Americans read the heartbreaking account of the president’s final moments, when his devastated wife, Ida McKinley, was brought in for a final farewell.

Czolgosz, apprehended on site, was convicted of first-degree murder and executed by electric chair on Oct. 29, 1901.

Famously notified of the assassination attempt while hiking in the Adirondack Mountains, the nation’s second-in-command, Theodore Roosevelt, made his way to Buffalo, but it was too late to speak to the president.

A former New York City police commissioner, state assemblyman and New York governor, the feisty Roosevelt became the nation’s youngest president at age 42.

Roosevelt and his wife Edith arrived in the White House with their six children, filling the Executive Mansion with energy and more than 40 typical and not-so-typical pets, according to the National Park Service. On the roster were a bear named Jonathan Edwards; a fleet of guinea pigs named Dr. Johnson, Admiral Dewey, and so on; a pig named Maude; multiple dogs; a hyena; a one-legged rooster; and sundry others.

Among the most celebrated society events of the Roosevelt presidency was the marriage of first daughter Alice Roosevelt to the charismatic Ohio Rep. Nicholas Longworth, 36, a future speaker of the U.S. House of Representatives, on Feb. 17, 1906, in a White House ceremony.

The 22-year-old Alice was the daughter of Roosevelt and his first wife, Alice Hathaway Lee, who died from kidney disease in 1884, just two days after giving birth.

The event was covered in the nation’s press as the “social event of the season,” attended by more than a thousand guests. The couple honeymooned in Cuba and toured Europe.

The marriage was a rocky and not a monogamous one — a condition unmet by both parties. Their daughter, Paulina, was widely acknowledged to be the daughter of Sen. William Borah of Idaho.

The 26th president pursued a reform agenda, an approach he called a “Square Deal” for Americans.

Known for bold rhetoric and bold action, Roosevelt pushed domestic policies through executive orders, legislation and a good deal of arm-twisting. He pursued antitrust actions against railroad and oil interests, uncovered and eliminated government corruption and expenditures, and operationalized oversight of the food and drug industries.

A fervent environmental advocate, Roosevelt worked with his secretary of the interior to enact a series of conservation measures. He established the U.S. Forest Service in 1905, created National Parks and Monuments, and fought for other protected lands.

Though many Washington insiders were not pleased with their feather-ruffling president, Roosevelt won a sweeping victory in the election of 1904 against a mostly forgotten opponent, Democrat and fellow New Yorker Alton B. Parker.

In critical industries such as oil, steel, finance, railroads and tobacco, America’s growing companies had been buying up and pushing out their competitors. Titans of industry made a fortune by consolidating control of production, distribution and markets.

As just one example, J.P. Morgan financed the merger of Carnegie Steel with multiple smaller companies to form U.S. Steel in 1901 — the largest company in the world at the time.

Andrew Carnegie personally received a quarter of a billion dollars in the deal (about $8.5 billion today).

While megalithic corporations were good for the bottom line, they were not good for competition, labor or the economic health of the nation, and the president soon had them in his crosshairs.

Under the Sherman Anti-Trust Act, Roosevelt and his Justice Department took aim at 45 companies, including Northern Securities, J.P. Morgan’s railroad conglomerate, in 1902; Swift Meatpacking Company in 1905; and Standard Oil in 1909.

As factories, railroads, highways, mills, bridges and coal mines became longer, larger and deeper, and as mechanization increasingly threatened the safety and even the lives of the labor force, many workers decided they had had enough.

A series of strikes in coal, steel and other industries during the decade made important progress toward labor reforms and safety legislation.

A wide-scale walkout of more than 100,000 Pennsylvania anthracite coal miners in the spring of 1902 threatened to leave hundreds of thousands of Americans in the cold as winter approached. In an unprecedented move, President Roosevelt intervened, appointing a committee to arbitrate a settlement. The miners returned to work and won a 10% increase in wages.

Mary “Mother” Jones, an Irish immigrant and former dressmaker, became one of the most famous — and feared — women in America when she led labor movements in the coal and textile industries. In 1903, she led a march of 100 children — some of whom had lost fingers or limbs in industrial accidents — from Philadelphia to New York to draw attention to the abuses of child labor.

Among the many others taking a stand during the decade were 5,000 mostly immigrant workers in McKees Rocks, Pa., who won an end to corrupt compensation practices in a 1909 strike against the Pressed Steel Car Company. That same year, more than 20,000 mostly young, mostly Jewish and Italian women garment workers went on strike in New York and Philadelphia, winning increased wages and improved working conditions.

Investigative journalists also disrupted the status quo in the decade of the 1900s.

For example, take journalist and civil rights leader Ida B. Wells-Barnett, who published “Mob Rule in New Orleans,” a graphic 1900 exposé on lynching in the South.

And don’t forget Titusville, Pa., native Ida Tarbell, daughter of a failed oil producer, who took on John D. Rockefeller in a scathing investigative 1902-1904 series on the Standard Oil Company in McClure’s Magazine.

And in 1906, Americans learned what really went into their processed meat, thanks to Upton Sinclair’s novel “The Jungle,” first published in the newspaper Appeal to Reason. The novel exposed the unsanitary conditions that plagued the meatpacking industry, including rotting carcasses, rat infestations and more.

This incisive investigative journalism came to be known as “muckraking,” a term coined by Theodore Roosevelt himself in an April 1906 speech.

The sobriquet was not intended as a compliment.

Roosevelt was critical of journalists who were fixated on bad news. But they fueled his reform agenda by revealing abuses in many industries, leading to meaningful reforms such as the Meat Inspection Act and the creation of the Food and Drug Administration in 1906.

About 9,000 automobiles plied the nation’s primitive roadways in 1900, according to the U.S. Department of Energy, but many Americans regarded these vehicles as impractical toys for the rich.

But the decade brought the first mass-produced auto: a one-cylinder, gasoline-powered 4.5 horsepower Oldsmobile Curved Dash Runabout. The bestselling car of 1902-1905, the Curved Dash sold for $650 (about $24,000 in 2025), according to The Henry Ford Museum.

Better remembered today is the Ford Model T, but it wasn’t the first Ford to make it big.

Like the rapid-fire release of iPhone variants a century later, Ford produced the Model A starting in 1903, followed by Model C, Model AC, Model K, Model S and then, in 1908, the Model T.

Assembly-line production eventually made the iconic roadster not only mass-produced but also “mass-affordable.” In production for nearly 20 years, more than 15 million units were manufactured, according to Ford.

With more American drivers now bouncing or sloshing along on unimproved roadways, the Office of Public Roads (later the Federal Highway Administration) undertook a nationwide inventory of roads in 1904.

The agency found that of the nation’s 2.1 million miles of rural public roads, a measly 7% had any type of “surface material.”

The finding prompted a rapid increase in spending on roads and bridges — including New York City’s iconic Queensboro and Manhattan bridges, both completed in 1909 — from $79 million in 1904 to $240 million one decade later.

Meanwhile, two brothers from Ohio were looking toward the skies for another breakthrough in transportation.

It was a windy December day on the coast of North Carolina when 32-year-old Orville Wright boarded the “Flyer,” a 12-horsepower, canard biplane with a 40-foot wingspan, for a flight of 120 feet in 12 seconds.

That same day, the Dayton-based brothers — Orville and 36-year-old Wilbur, both high school dropouts — completed three more gasoline-powered flights near Kitty Hawk, proving that sustained air travel was possible.

By the end of the decade, the airplane was featured in public exhibitions and driving new aerial military strategies. Commercial air travel, however, would have to wait.

“Thousands of human lives are crushed under the ruins,” The Grand Forks, N.D., Evening Times reported in its April 18, 1906, morning edition. “Scenes of horror are heartrending and [the] fire fiend adds to death’s awful harvest.”

Sleeping residents had been jarred awake that Wednesday at about 5 a.m. by the estimated 7.9 magnitude earthquake, the result of an offshore slip on the San Andreas Fault.

Despite attempts to rescue victims, as many as 3,000 were killed by collapsing buildings or in the subsequent fires, according to the U.S. Geological Survey, making the 1906 earthquake the deadliest natural disaster in California history.

With over 28,000 buildings destroyed, more than half the city’s 400,000 residents were homeless. Their makeshift tent cities, erected in nearby parks and beaches, remained for more than two years, according to the U.S. Army Corps of Engineers.

All told, the earthquake and fires destroyed nearly 500 city blocks and accounted for more than $10 billion in damage in 2025 dollars, according to the Corps.

Across the country, New York newspapers were curious about an outbreak of typhoid fever among a number of New York’s elite families.

A private investigator determined that the victims shared something in common: their cook, Mary Mallon, an asymptomatic carrier of the life-threatening digestive tract infection, which causes fever, pain and diarrhea.

The New York City Health Department ordered Mallon arrested as a “public health threat.”

“Typhoid Mary” was quarantined in a harbor island hospital twice, from 1907 through 1910, and again beginning in 1915, after secretly returning to her former career and infecting another group of people.

Mallon later acknowledged that she rarely washed her hands — a practice that was not universally adopted at the time.

She remained incarcerated until her death in 1938.

The “Boston Americans have [the] advantage” after seven games in the new “World’s Championship,” the St. Louis Republic declared at the head of its Oct. 13, 1903, sports page, but the “Pirates will try hard.”

The matchup pitted legendary Boston pitcher Cy Young against Pittsburgh’s power-hitting shortstop Honus Wagner. Games were played at the Pirates’ home field, Exposition Park in Allegheny, Pa., a few blocks west of today’s PNC Park, and at Boston’s Huntington Avenue Baseball Grounds, property that is today part of Northeastern University.

Sadly, the Pittsburgh Pirates’ efforts would not be enough. They lost baseball’s first World Series to the future Red Sox, five games to three.

The Pirates would avenge their 1903 loss in 1909 with a seven-game World Series win against the Detroit Tigers and their “Georgia Peach,” center fielder Ty Cobb. With the first of five World Series championships in hand, the decade would come to a glorious end — for Pittsburghers, at least.