What is the name of the oldest commissioned vessel in the U.S. Navy?

The oldest commissioned vessel in the U.S. Navy is the USS Constitution, launched in 1797. This ship is famously known as "Old Ironsides" due to its impressive durability in battle, particularly during the War of 1812. The USS Constitution holds a prominent place in naval history not only because of its age but also due to its role in establishing the U.S. Navy's reputation as a formidable maritime force. It is currently preserved as a museum ship in Boston, Massachusetts, where it serves as a major historical artifact and a symbol of U.S. naval heritage.

In comparison, the other vessels listed do not have the same historical standing regarding their active service status. The USS Arizona, for instance, is a World War II battleship that was sunk during the attack on Pearl Harbor and is now a memorial. The USS Constellation, also an important ship, served during the 19th century but was not commissioned before the Constitution. The USS Enterprise, known for its role in the latter half of the 20th century, represents an iconic class of aircraft carriers but does not match the age of the Constitution. Thus, the USS Constitution's continuous commission since its launch makes it the correct answer in this context.