Leaving its stamp on history: This 3-cent U.S. stamp was issued on Dec. 30, 1953, to mark the 100th anniversary of the Gadsden Purchase.
1854 Gadsden Purchase
The Tucson Presidio was part of the 29,670-square- mile swath acquired for $10 million from Mexico — primarily to build a southern transcontinental railroad line. Arizona became a separate U.S. territory in 1863 and, after a contentious political process, finally gained statehood in 1912.

