The Hoover Dam, the subject of the new Express Mail stamp, was named for former President Herbert C. Hoover in 1931. The dam is a national historic landmark and is located on the Arizona-Nevada border, 30 miles southeast of Las Vegas. The structure is the nation’s tallest concrete dam and was the tallest dam ever built when completed in the mid-1930s.
The Priority Mail stamp features an illustration of Mount Rushmore National Memorial, located in the Black Hills of South Dakota. Completed in 1941, the monument features large-scale sculptures of four American presidents — George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln.