On May 1, 1863, Peace Democratic Party leader Clement L. Vallandigham spoke to 10,000 people from this spot. His party, known by opponents as Copperheads, opposed the Civil War as an encroachment on both individual and states' rights and favored a peaceful settlement with the Confederacy. After President Lincoln suspended the writ of habeas corpus as an emergency wartime measure, Peace Democrats viewed the suspension as unconstitutional. Vallandigham's speech intentionally tested stringent wartime laws against implied treason. After two years of bloody battles with few Union victories, the Lincoln administration faced losing influence in several northern states, and Lincoln feared Midwestern dissent as a greater threat to the Union than military reverses. General Ambrose Burnside ordered Vallandigham arrested, and Lincoln then banished him to the South. Vallandigham evaded the federal naval blockade and traveled to Canada, where he campaigned in exile for the governorship of Ohio. Union victories at Gettysburg and Vicksburg in July 1863 defused the Peace movement and helped assure Lincoln's reelection. Vallandigham's arrest was the greatest challenge to free speech during the war.