being "local" ground forces affiliated with the army, militias were considered state-centric/territorial-centric in nature, this versus naval forces, which were considered wholly activities of the federal government. this distinction accounts for why there are no national guard components in the u.s. navy, u.s. marine corps or u.s. coast guard. because the present day u.s. air force evolved from the u.s. army, it was only natural that a separate air national guard would be established with the divestiture of the former u.s. army air forces and its establishment as a separate and independent u.s. air force in 1947.