On September 17, 1861, the first day of the Maryland legislature's new session, fully one third of the members of the Maryland General Assembly were arrested, due to federal concerns that the Assembly "would aid the anticipated rebel invasion and would attempt to take the state out of the Union." Although previous secession votes, in spring 1861, had failed by large margins, there were legitimate concerns that the war-averse Assembly would further impede the federal government's use of Maryland infrastructure to wage war on the South.