John Brown organized the Chatham convention in Ontario to discuss his “Provisional Constitution.” The convention began on May 8, 1858 with white and black anti-slavery activists attending. It was held at a black schoolhouse to avoid interference by curious, white Chatham residents. At the convention Brown spoke about his plan to establish a military stronghold in the mountains that runaway slaves could use as a haven and choose to join his militant cause. Brown’s Provisional Constitution also mentioned his plans for an insurrection—his attack on Harpers Ferry. Though invited, national figures like Frederick Douglass and Jermain Wesley Loguen did not attend.