In April 1936, a bill was introduced in the House of Representatives that called for 50-cent pieces "to indicate the interest of the Government of the United States in the fulfillment of the ideals and purposes of the celebration commemorating the achievements of Capt. Henry Miller Shreve." The coins were to be issued "in connection with the celebration of the one hundredth anniversary of the opening of the TriState Territory of east Texas, north Louisiana, and south Arkansas by Capt. Henry Miller Shreve."
What is meant by "opening of the TriState Territory?" It has to do with the effort to clear the Red River of accumulated tree trunks, limbs, miscellaneous driftwood and other similar debris. The river had a history of collecting such debris and the accumulation had grown so large it was referred to as "The Great Raft." The river's winding path and the riverbed's soft, rock-free soil were natural enablers of the accumulation of tree debris resulting from heavy rains and other storms; the accumulations eventually grew to a size that blocked navigation and hurt trade/commerce in the region.
Based on his past successes elsewhere using equipment of his own's invention, Captain Henry Miller Shreve, US Superintendent of Western River Improvement, was assigned to clear the debris and create more navigable waters within the river in 1833. He choose to establish a campsite for his works on a bluff overlooking the river, which Ultimately became the permanent settlement of Shreveport, LA (Yes, it took its name from Captain Shreve.) His efforts cleared commercial shipping lanes and led to the opening of southern Arkansas and northern Louisiana to further development. Red River Watershed Map(Image Credit: Shannon1 - Drawn by myself; shaded relief data from NASA SRTM North America imagery here, CC BY-SA 4.0, https://commons.wikimedia.org/w/ind...d=12125593).
The bill called for up to 50,000 standard-specification half dollars with "a special appropriate design or designs to be fixed by the Director of the Mint, with the approval of the Secretary of the Treasury." The sponsor behind the coin bill was Shreveport Centennial, Inc.
The bill was referred to the House Committee on Coinage, Weights, and Measures where it was received and reported favorably. The bill moved through the House without issue and was sent to the Senate for consideration - that's when things took a turn.
Once received in the Senate, it was referred to the Committee on Banking and Currency. The Committee recommended an amendment via substitution, replacing the entire text of the bill (after the enacting clause) with provisions calling for 25,000 commemorative medals rather than 50,000 half dollars. The amendment did not specify the single composition to be used (i.er., gold, silver, bronze) but did specify that the medals could only be struck at a single US Mint facility, and could only be one size and weight (no Norse-American Centennial repeat!).
The amended bill was passed by the Senate without issue and sent back to the House for its consideration. The bill was called up in the House and the Senate amendments were agreed to without debate. The bill was then signed in each chamber and sent on to the President for final approval and signature. US President Franklin Delano Roosevelt signed the bill into law on June 25, 1936.
Shreveport Centennial, Inc. decided against having the US Mint strike its medals. They likely decided that selling medals was already going to be a difficult task (vs. coins) and the difficulty would only be compounded by the fact that the Shreveport Centennial was officially celebrated the year prior, in 1935. So. no US Mint-struck coin or medal!(Note: From what I can find, the 1935 Shreveport Centennial/Caddo Indian Treaty medal that is often encountered in the market was sponsored by a different group vs. Shreveport Centennial, Inc.)