Breen

The word Breen is forever associated with die varieties due to the extensive research and reporting of Walter Breen. Breen's Complete Encyclopedia of U.S. and Colonial Coins catalogues approximately 8,000 varieties across all U.S. coinage. Accordingly, many VAMs are cross-referenced as Breen varieties, which themselves are listed in sequential numerical order beginning with colonial coinage.
Morgan Varieties constitute Breen #5497-5711, while Peace varieties span Breen #5712-5742.
Some of the more famous Morgan varieties cross-referenced:
1878-P 7/8tf VAM-44 - Breen #5506 (which includes a few other 7/8tf varieties)
1880-CC VAM-4 - Breen #5551
1880-CC VAM-6 - Breen #5554
1882-O/S all VAMs - Breen #5567
1887-P VAM-2 - Breen #5593
1887-O VAM-3 - Breen #5597
1888-O VAM-4 - Breen #5603
1890-CC VAM-4 - Breen #5618
1895-S VAM-3 - Breen #5640
1895-S VAM-4 - Breen #5641
1900-O/CC all VAMs - Breen #5673
1901-P VAM-3 - Breen #5680
1903-S VAM-2 - Breen #5697
Many famous Morgan die varieties are not mentioned in Breen's Encyclopedia, which one could not expect to be exhaustive given the broad nature of its listings across all U.S. coinage. Some of the varieties absent include 1878-P VAM-9 "First Variety," 1887-P VAM-1A "Donkey Tail," 1888-O VAM-1B "Scarface," and 1921-D VAM-1A2 "TRU-T."
Please click this link for the full VAMworld.com definitions page.