Less than one (1) month following the assassination of President Abraham Lincoln a military ccommission was convened to try nine (9) alleged Confederate sympathizers charged with conspiring to assassinate Lincoln, Secretary of State William Seward, and Vice President Andrew Johnson. Two (2) months and 23 days following the assassination, four of nine were executed after being found guilty. On the morning of the execution, marshals attempted to serve a writ of habeas corpus challenging the constitutionality of the death sentences. However, the marshals were turned away at the gates of the Washington Arsenal, the location of the hangings. Johnson canceled the writ under the Habeas Corpus Suspension Act of 1863. Today is the anniversary of those executions.