The Thomson–Urrutia Treaty was signed on April 20, 1921 between the United States and Colombia. Based on the terms of the agreement, the U.S. paid Colombia 25 million dollars in return for Colombia's recognition of Panama's independence. This resolved the United States support of the separation of Panama from Colombia in 1903. It was successfully negotiated and signed by the US on April 6, 1914 and ratified by Colombia on June 9 of that year but not ratified by the US until 1921.
- Lael, Richard L. (1978). "Struggle for Ratification: Wilson, Lodge, and the Thomson-Urrutia Treaty". Diplomatic History. 2: 81–102. doi:10.1111/j.1467-7709.1978.tb00423.x. Retrieved August 15, 2012.
- Francisco Escobar (Jul 13, 1914). "Why the Colombian Treaty Should be Ratified". The Independent. Retrieved August 14, 2012.