This unique cover commemorates the last day in commission of the USS Sam Houston SSBN-609, which served in the United States Navy. The cover features a cachet autographed by the commanding officer and was postmarked on September 27, 1991. 

USS Sam Houston (SSBN-609/SSN-609), an Ethan Allen-class submarine, was the second ship of the United States Navy to be named after Sam Houston (1793–1863), president of the Republic of Texas (1836–1838, 1841–1844). Sam Houston was the US Navy's seventh ballistic missile submarine