This series has been divided into 33 additional sub-series:
A. New York
B. Pennsylvania
C. Massachusetts
D. Connecticut
E. District of Columbia
F. New Jersey
G. Virginia
H. New Hampshire
I. Vermont
J. Illinois
K. Missouri
L. Ohio
M. Kentucky
N. California
O. Colorado
P. Georgia
Q. Michigan
R. Wisconsin
S. Delaware
T. Rhode Island
U. Maine
V. Indiana
W. Tennessee
X. South Carolina
Y. North Carolina
Z. Louisiana
AA. Florida
AB. Alabama
AC. Texas
AD. Mississippi
AE. Hawaii
AF. Iowa
AG. British Isles