A half dollar is a coin in the United States that is worth 50 cents. It is made of a combination of copper and nickel and has been in circulation since 1794. The coin features a portrait of John F. Kennedy on the front, which was introduced in 1964 after his assassination. Half dollars are larger than a quarter but smaller than a silver dollar. They are often used in coin collecting and can be found in circulation, although they are less common than other coins like the penny or nickel. The coin's design has changed over the years, featuring various symbols and figures.