In what year was the minimum voting age in the U.S. changed to 18?

The minimum voting age in the United States was changed to 18 years old with the ratification of the 26th Amendment to the Constitution in 1971. This amendment was significant because it recognized the rights of younger citizens, particularly those who were being drafted for military service during the Vietnam War, to participate in the electoral process. The amendment was quickly proposed and ratified in response to the growing momentum for change in voting rights during the 1960s and early 1970s. Thus, the selection of 1971 as the year when the voting age was lowered to 18 is accurate.