Authorization for the 1926 American Independence Sesquicentennial Silver Half Dollar and Gold Quarter Eagle (2.50) began as a Joint Resolution introduced in the Senate in February 1925, during the Second Session of the 68th Congress; it was introduced by Senator George Wharton Pepper (R-PA). The Resolution was not specifically about commemorative coins, however, it set the stage for the United States Government to participate in the US Sesquicentennial Exposition to be held in Philadelphia in 1926 and specified that foreign articles brought into the United States for the "sole purpose of display at such exhibition" shall be tariff-free.
The Title of the Resolution was: "Providing for the cooperation of the United States in the sesquicentennial exhibition commemorating the signing of the Declaration of Independence, and for other purposes." Authorization for the commemorative coins was one of the "other purposes" within the Resolution.
The Resolution established the National Advisory Commission to the Sesquicentennial Exhibition Association...to confer with and advise the officers and directors of the Sesquicentennial Exhibition Association, in connection with the holding, under the auspices of such association, of a national and international exhibition in the city of Philadelphia, Pennsylvania, in 1926, in celebration of the one hundred and fiftieth anniversary of the signing of the Declaration of Independence." It appropriated $25,000 for Commission expenses.
In further support of the Exhibition Association , the Resolution also authorized the silver and gold commemorative coins with which collectors are familiar. I've discussed before how the Resolution called for a gold coin of the denomination $1.50, but that it was later amended (in the House of Representatives) to a Gold Quarter Eagle coin ($2.50) to bring it in line with then-current
US coinage standards.
The Resolution originally called for up to 500,000 gold coins and up to 1 million silver 50-cent pieces. The gold coin mintage limit would later be revised to no more than 200,000 gold coins (in the House); the limit for the silver 50-cent pieces remained at 1 million in the version of the Resolution that became law.
The legislation did not face serious objection while being considered in either chamber, just a few technical amendments. It was signed into law by US President Calvin Coolidge on March 3, 1925.
The 1926 Sesqui Gold Quarter Eagle is generally the most budget-friendly of the US classic-era gold coins.
1926 American Independence Sesquicentennial Gold $2.50


For other of my posts about commemorative coins and medals, including more on the 1926 Sesqui half dollar, see:
Commems Collection.