While the former president is no longer in office, Sheehan has she said her issues with Bush didn't end with his presidency.
Sheehan was arrested outside the White House earlier this month while taking part in a protest aimed at ending the wars in Afghanistan and Iraq. Sixty other protesters were also taken into custody.
The group was demanding a meeting with President Obama, and also said they wanted to close the prisons at Guantanamo and Bagram, plus spend the money used for the surge in Iraq for housing and jobs here in the US.
Organizers of Tuesday's event said admission was free, but donations are accepted.