The U.S. nautical Union Jack is a historic American maritime flag featuring a blue field with white stars. It is traditionally associated with the United States Navy and is flown from the jackstaff at the bow of a vessel rather than from the stern, where the national ensign is displayed.
The best-known U.S. Union Jack is the 50-star Union Jack, which became the Navy jack on June 4, 1960, following the admission of Hawaii as the 50th state. Earlier versions featured fewer stars and corresponded to the number of states in the Union at the time.
Historically, the U.S. Navy has also used special Union Jack designs, including the First Navy Jack, which features thirteen alternating red and white stripes with a rattlesnake and the motto “Don’t Tread on Me.”
Today, U.S. nautical Union Jacks are popular with boaters, sailors, yacht clubs, maritime-history enthusiasts, and collectors of American naval flags.