 This club became part of the Maryland National Guard in 1921 when Maryland formed one of the nation's first post-war flying units with the creation of the 1st Observation Squadron in Baltimore which received federal recognition on 29 June 1921.Maryland became the fifth state to have a post-World War I National Guard aviation unit.The 1st Observation Squadron (a state designation) was re-designated the 104th Squadron (Observation) under the federal numbering system.