Back in 1914, two similar bills were introduced in the Senate that called for a circulating 25-cent coin to "commemorate the opening of the Panama Canal and the centenary of peace."
The "centenary of peace" referred to the ongoing peaceful relations between the United Kingdom and the United States since the end of the War of 1812 via the signing of the Treaty of Ghent. The Treaty was signed in Europe on December 24, 1814, but it was not ratified by the US Senate until February 18, 1915.
After roughly ten years of planning, infrastructure preparation and actual construction, the Panama Canal had its official opening on August 15, 1914. It was definitely one of the most impressive engineering feats of its day (or any day) and worthy of being celebrated!
Neither of the bills was successful, however, and the opportunity to produce the first "on purpose" US circulating commemorative coin was lost. Of course, 20 years before, the 1892-93 Columbian half-dollars transitioned from their intended purpose of "commemorative souvenir" to "circulating coinage" when roughly a million unsold pieces were dumped into circulation after the Columbian Exposition closed.
As no coin was struck for either of the failed bills, I present here a few "substitutes." First up, a commemorative medal struck by Tiffany & Company for the Peace Centennial; the medal was the official issue of the American Peace Centenary Committee. Also shown is the Panama-Pacific Exposition commemorative half-dollar and one of the Mint's commemorative medals for the Exposition. The Panama-Pacific International Exposition was staged in 1915 and 1916 as a grand commemoration of the Canal's opening.
1915 Peace Centennial Medal - Obverse
1915 Peace Centennial Medal - Reverse
1915 Panama-Pacific Exposition Half-Dollar - Obverse
1915 Panama-Pacific Exposition Half-Dollar - Reverse
1915 Panama-Pacific Exposition Medal - Obverse
1915 Panama-Pacific Exposition Medal - Reverse