PHILADELPHIA — The opening of a planned memorial marking the spot where George Washington lived as president with a number of slaves has been postponed until next fall.

Officials had planned to open the President's House in time for Independence Day, and they even hoped that President Obama might attend. But the city and Independence National Historical Park say the opening is being pushed back to allow further revision of interpretive materials to better portray slavery in the nation's early days.

"We wanted to take a step back and figure out a more compelling way to tell this complex story," project director Rosalyn McPherson said Thursday.

The planned explanatory displays have been the subject of controversy as officials try to balance describing the home of presidents George Washington and John Adams just steps from Independence Hall and the stories of the nine slaves Washington kept there.

Attorney Michael Coard, a member of the oversight board, says an extension is needed to get the portrayal right.