On April 6, 1866, Benjamin Stephenson of Decatur Illinois formed a society for veterans known as the Grand Army of the Republic (GAR). The G.A.R. would grow into one of the most decisive organizations in United States politics and policy and at its peak contained over 400,000 members. It was structured regionally, with members in every state. This structure consisted of a web of subsidiary groups with 'Posts' on the regional level and 'Departments' mandating on the state level.