<Tr> <Td> Secretary of Defense (10 U.S.C. § 113) </Td> <Td> James Mattis </Td> <Td> January 20, 2017 </Td> </Tr> <Tr> <Td> Attorney General (28 U.S.C. § 503) </Td> <Td> Jeff Sessions </Td> <Td> February 9, 2017 </Td> </Tr> <Tr> <Td> Secretary of the Interior (43 U.S.C. § 1451) </Td> <Td> Ryan Zinke </Td> <Td> March 1, 2017 </Td> </Tr> <Tr> <Td> Secretary of Agriculture (7 U.S.C. § 2202) </Td> <Td> Sonny Perdue </Td> <Td> April 25, 2017 </Td> </Tr>

What is the second largest united states cabinet department