One of the least understood military organizations in the history of the United States were the sea fencibles companies which were created during the War of 1812 by both the federal government and by some of the states. The U.S. Corps of Sea Fencibles was a unique branch of the U.S. Army. The U.S. Corps of Sea Fencibles consisted of U.S. Army officers and seamen in the enlisted ranks. They were a very unique corps which not only operated heavy canons but they could also man harbor gunboats and serve as infantry when needed. Various states also created their own sea fencibles companies which protected their ports and harbors. With most of the nation's merchant ships tired up in the ports along our eastern seaboard due to the British blockade during the war, there were plenty of unemployed sailors who needed jobs. This book lists all of the companies, both federal and state, along with a short history for each company. Plus, the book lists the 979 known men who served in the U.S. Corps of Sea Fencibles and the 1,916 known men who served in the various state sea fencibles companies. Mr. Johnson is a lineal descendant of five veterans of the War of 1812 and he is the past president of the Society of the War of 1812 in the State of Ohio (2008-2011). He is currently the Archivist General for the General Society of the War of 1812 and has served as the Historian General (2011-2014) for this society.