They were dressed in orange jump suits in scenes similar to the video released showing the killing of 21 Copts by IS in Libya.
Last week IS posted a video on social media appearing to show the killings of the Coptic Christians it had abducted.
"Obama, Obama, did you see? Christian blood in the sea," the demonstrators shouted.
Outside the White House the men knelt with their hands behind their backs whilst other protesters stood behind them holding photographs of the men murdered.
Almost 50 people marched down Capitol Hill calling on the US Government to take more action in the battle against Islamic extremism.