<Table> <Tr> <Th_colspan="2"> Veterans Day </Th> </Tr> <Tr> <Td_colspan="2"> World War I veteran Joseph Ambrose attends the dedication parade for the Vietnam Veterans Memorial, holding the flag that covered the casket of his son, killed in the Korean War . </Td> </Tr> <Tr> <Th> Observed by </Th> <Td> United States </Td> </Tr> <Tr> <Th> Type </Th> <Td> National </Td> </Tr> <Tr> <Th> Date </Th> <Td> November 11 (fourth Monday in October, 1971--1977) </Td> </Tr> <Tr> <Th> Frequency </Th> <Td> Annual </Td> </Tr> <Tr> <Th> Related to </Th> <Td> Armistice Day, Memorial Day, Remembrance Day </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Veterans Day </Th> </Tr> <Tr> <Td_colspan="2"> World War I veteran Joseph Ambrose attends the dedication parade for the Vietnam Veterans Memorial, holding the flag that covered the casket of his son, killed in the Korean War . </Td> </Tr>

When did veterans day become a federal holiday