In the years following the war, more than ten GAR posts were established in Westchester. GAR Post #466, James Cromwell Post, was mustered on March 19, 1884. The incorporation document for the post shows the name of Weitzel Post. This name was soon changed to James Cromwell when it was discovered that another GAR post already bore the name Weitzel. The post's first commander, White Plains resident Valentine M. Hodgson, was a lieutenant in the 67th New York Infantry.

Each post kept records, including lists of members, initiation fees and dues, such as this example from GAR Post #60, Kitching Post of Yonkers. The book covers member activities from 1903-1907. GAR members often changed posts. Captain John Gedney of White Plains, who fought with the 6th New York Heavy Artillery, was originally affiliated with Kitching Post; later he belonged to Cromwell Post.