If US Secretary of the Treasury Andrew Mellon had his way, the classic-era series of US commemorative coins would not include the 1925 Fort Vancouver Centennial Half Dollar (nor the 1925 California Statehood 75th Anniversary or the 1927 Battle of Bennington / Vermont Independence Sesquicentennial half dollars - at a minimum).
In early 1925, Secretary Mellon wrote to US President Calvin Coolidge expressing his objection to the US Government "permitting its coinage system to be commercialized for profit of any celebration, whether national in scope or not." He urged Coolidge to veto the commemorative coin bills before him.
Under consideration by Coolidge at the time were the three half dollars referenced above. Regarding these, Mellon wrote: "Each case is precedent for the next case, and we must draw some limit to the diversion of our currency from its legitimate purpose as a means of payment by the general public for its business transactions, to a means of profit to particular bodies."
Of course, Coolidge did not veto the combined bill that authorized the three half dollars and signed their bill on February 24, 1925 - the US commemorative coin series continued.
Calvin Coolidge, though under regular pressure from the Treasury Department, did not veto any commemorative coin bills - that distinction would fall first to his successor, Herbert Hoover, via the Gadsden Purchase 75th Anniversary coin bill (April 1930). (See:
What If? 1930 Gadsden Purchase.)
1925 Fort Vancouver Centennial Half Dollar

For other of my posts about commemorative coins and medals, including more Fort Vancouver half dollar stories, see:
Commems Collection.