The year 1936 is often pointed to as the pinnacle year for the classic-era US commemorative coin series - the peak of the boom market for US commemorative coins. 1936 saw five continuation issues of coins previously authorized (e.g., Oregon Trail Memorial), 16 new authorizations and 18 total issues (or 21 total issues if you include the three commemorative coins for the US-Philippines Commonwealth establishment).
Note: Three commemorative half dollars were authorized in 1936, but not made available until 1937 (even though they were dated "1936"). They were: the Norfolk, Virginia, the Delaware Tercentenary and the Battle of Gettysburg coins.In 1937, there were two new COIN authorizations that were issued (Roanoke Colony, Battle of Antietam), four continuation issues of coins previously authorized (e.g., Oregon Trail Memorial), three releases of coins authorized in 1936 (see Note) and one coin authorized but not dated/released until 1938 (New Rochelle, NY).
1937 was, however, a boom year for commemorative coin proposals - roughly four dozen such proposals were introduced in Congress in 1937. If Congress' "open-door" policy toward new commemorative coin proposals had continued in 1937, it's plausible to believe that an additional 20+ coins would have been approved. Add 20+ new coins to those already issued in 1937 and a new "boom year" is created.
If you'd like to review the 1937 proposals, visit:
Commems Collection ND CHECK OUT THE "wHAT iF?" LIST.