<Table> Half dollar <Tr> <Td_colspan="2"> United States </Td> </Tr> <Tr> <Th> Value </Th> <Td> 0.50 U.S. dollar </Td> </Tr> <Tr> <Th> Mass </Th> <Td> 11.340 g (0.365 troy oz) </Td> </Tr> <Tr> <Th> Diameter </Th> <Td> 30.61 mm (1.205 in) </Td> </Tr> <Tr> <Th> Thickness </Th> <Td> 2.15 mm (0.085 in) </Td> </Tr> <Tr> <Th> Edge </Th> <Td> 150 reeds </Td> </Tr> <Tr> <Th> Composition </Th> <Td> 91.67% Cu 8.33% Ni </Td> </Tr> <Tr> <Th> Years of minting </Th> <Td> 1794--present </Td> </Tr> <Tr> <Th> Catalog number </Th> <Td>--</Td> </Tr> <Tr> <Th_colspan="2"> Obverse </Th> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Design </Th> <Td> John F. Kennedy </Td> </Tr> <Tr> <Th> Designer </Th> <Td> Gilroy Roberts </Td> </Tr> <Tr> <Th> Design date </Th> <Td> 1964 </Td> </Tr> <Tr> <Th_colspan="2"> Reverse </Th> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Design </Th> <Td> Presidential Seal </Td> </Tr> <Tr> <Th> Designer </Th> <Td> Frank Gasparro </Td> </Tr> <Tr> <Th> Design date </Th> <Td> 1964 </Td> </Tr> </Table> <Tr> <Td_colspan="2"> United States </Td> </Tr>

When was the first 50 cent piece made