I've mentioned before how maintaining ongoing interest in the Oregon Trail Memorial half dollars was attempted by assigning names to the coins for a portion of its issues. Development of the names appears to have been a joint effort between the Oregon Trail Association and Scott Stamp & Coin Co. of New York ("Scott"). Scott took over distribution of the coins in 1933 and continued in the role into 1936; distribution responsibility for the coins reverted back to the Trail Association beginning with the 1937 issue.
The coins were first formally marketed with their applied names in the September 1934 issue of
The Coin Collector's Journal, the house publication of Scott. The names were applied retroactively to the previous issues.

The initial issue, the coins of 1926, were referred to as the "Ezra Meeker" coins. Meeker, of course, was the primary driver behind the memorial coins and the leading proponent of preserving and marking the original Oregon Trail. He was also the first President of the Oregon Trail Memorial Association.

The 1928 issue, struck in Philadelphia, was referred to as the "Jedediah Smith" coin. Smith was a hunter/trapper and explorer; in 1828, he led an expedition from Northern California into Oregon and is remembered for his "Master Map" of the area.

The 1933 issue from Denver was termed the "Century of Progress" coin. The coins were sold at the Century of Progress International Exposition in Chicago in 1933 and 1934.

The 1934 release from Denver was marketed as the "Fort Hall, Fort Laramie, Jason Lee Centennial" coin. (See ad below for details.)

The 1936 issue from Philadelphia and San Francisco were termed the "Whitman Mission" coins. (See link below for more.)
The practice stopped after 1936, with neither the 1937, 1938 nor 1939 coins being tagged with a historical reference (these issues were post-Scott). From looking at contemporary advertisements for the Oregon Trail coins, it does not appear that the historical name tags ever achieved any sort of traction among coin dealers (outside of Scott) -- the coins were typically just listed as "Oregon Trail" by date in advertisements.
In 1934, Scott and the Association worked to highlight the history behind the year's coin issue. The April 1934 issue of
The Coin Collector's Journal included an article by Howard Driggs, President of the Oregon Trail Memorial Association. The piece was titled "Two Historic Centennials on the Old Oregon Trail" and presented the stories of Fort Hall and Fort Laramie.
Later in the year, in August, Driggs returned to the pages of
The Coin Collector's Journal with a piece titled "A Tri-Centennial Coin." It updated the April article with background information on Jason Lee, the Methodist missionary who endeavored to bring the "White Man's Book of Heaven" to the Native Americans. The article ran as a full-page advertisement in the American Numismatic Association's
The Numismatist magazine; the magazine also included a full-page sales ad from Scott for the 1934 coins.
The Scott story-ad and sales ad follow:
Oregon Trail Memorial Half Dollar - 1934 Centennials - Association-Scott Advertisement, ANA The Numismatist, September 1934
1934 Oregon Trail Memorial Half Dollar - Scott Coin and Stamp Co. Sales Ad - ANA The Numismatist, September 1934
1926 Oregon Trail Memorial Half Dollar

For more on the Oregon Trail half dollar, check out:
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1926 Oregon Trail Memorial-
1928 Oregon Trail Memorial-
What If? 1926 Oregon Trail Memorial MedalFor more on the related 1936 Whitman Mission Centennial coin proposal:
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What If? 1936 Whitman Mission CentennialFor other of my posts about commemorative coins and medals, including more on the Oregon Trial coin, check out:
Commems Collection