The Oregon Trail Memorial coin's authorized mintage of 6 million and the 5 million authorized for the Booker T. Washington half dollar certainly catch one's attention - but what would you say to a commemorative coin with a potential maximum mintage of 40 million? (!)
In 1928, Representative Miles Clayton Allgood (D-AL) introduced a bill in the House that proposed "to have stamped into the coinage of the United States of America from silver bullion $20,000,000 in denominations of 50 cents each." The coins were to feature "a design appropriate to commemorate the outstanding achievements of Colonel Charles A. Lindbergh in making the first nonstop flight across the Atlantic; for other great accomplishments in aviation; and to lend additional aid to the 'Good-will ambassador' in furthering commercial aviation."
Considering the number of coins requested, it would seem as if a circulating commemorative coin was being proposed. This was not the case, however, as the coins were to be delivered only to an Executive Committee appointed by Lindbergh; the bill did not restrict orders for the coins in terms of minimum quantities per order or a time frame for ordering. Per the bill, as long as the Committee paid for them, it could decide the "When?" and "How many?" for each order. Even though Colonel Lindbergh enjoyed tremendous popularity at the time - his nonstop flight from New York to Paris took place just months before - May 20 to May 21, 1927 (the solo flight took 33.5 hours) - I believe expecting the public to purchase 40 million half dollars at a premium above face value (however small or large it might be) would have been extremely optimistic.
Colonel Charles Lindbergh Standing in Front of His Plane - The Spirit of St. Louis
(Image Credit: Library of Congress, https://www.loc.gov/pictures. Public Domain.)The coin bill was not nearly as successful as Lindbergh's flight, however, as it was not supported by the Treasury Department and was never reported out by the House Committee on Coinage, Weights, and Measures - it had been referred to the Committee upon its introduction. The coin bill competed against companion bills for 10 million commemorative medals plus a bill calling for a gold medal to be presented to Lindbergh on behalf of Congress, along with bronze duplicates to be sold to the public. The gold/bronze medal proposal was the only proposal to be passed by Congress; the bronze medal became a popular piece in the Mint's catalog.
US Mint Charles Lindbergh Bronze Medal

The medal was designed/sculpted by
Laura Gardin Fraser. It was originally available from the Mint in 1928 (List Medal Number 645), and has been re-struck multiple times over the years. Unfortunately, the medal has not been available from the Mint for ~40 years (early 1980s). Examples of the medal can generally be found in the secondary market (that's where I got mine!).