The petitions opposed use of military force to resolve the festering dispute over Iran's nuclear program.
The California woman whose son was killed in Iraq more than two years ago was taken into custody with three other women on the sidewalk outside the White House gate, said Lt. Scott Fear, a U.S. Park Police spokesman. They were charged with interfering with a government function, he said.
"It was taking too long for them to decide whether to accept them or not, so we just delivered them," said Sheehan. The petitions were tossed over the wrought-iron fence after the protesters waited about 15 minutes without a response.
Sheehan, 49, and other grieving families met with Mr. Bush about two months after her son died, before reports of faulty prewar intelligence surfaced and caused her to speak out. She has tried repeatedly to speak with the president again, including by mounting a 26-day vigil last year outside Mr. Bush's ranch in Crawford, Texas.
Wednesday's protest came as Republicans lost control of Congress and Mr. Bush announced the resignation of Defense Secretary Donald Rumsfeld.
"He's being offered as a sacrificial lamb," Sheehan said.