The following patterns can be used to extract state information.
'''a. '[,] State Postcode''''
The state and postcode are always together, separated by a space. We can extract state information with regular expression
THEN 'D.C.'
'''d. 'A CORP.* OF [State]''''
This pattern is not reliable. When 'addrline1' looks this way, 'addrline2' always provide more detailed address information than 'addrline1'. Besides, a great part of state info extracted from 'A CORP.* OF [State]' doesn't match the state extracted from detailed 'addrline2'. In this way, we discard this pattern.