Question: which factor contributed most to the u.s. acquisition of florida in 1819

title: Adams–Onís Treaty
text: The Adams -- Onís Treaty of 1819 , also known as the Transcontinental Treaty , the Florida Purchase Treaty , or the Florida Treaty , was a treaty between the United States and Spain in 1819 that ceded Florida to the U.S. and defined the boundary between the U.S. and New Spain . It settled a standing border dispute between the two countries and was considered a triumph of American diplomacy . It came in the midst of increasing tensions related to Spain 's territorial boundaries in North America against the United States and Great Britain in the aftermath of the American Revolution ; it also came during the Latin American wars of independence . Florida had become a burden to Spain , which could not afford to send settlers or garrisons . Madrid decided to cede the territory to the United States through the Adams -- Onís Treaty in exchange for settling the boundary dispute along the Sabine River in Spanish Texas . The treaty established the boundary of U.S. territory and claims through the Rocky Mountains and west to the Pacific Ocean , in exchange for the U.S. paying residents ' claims against the Spanish government up to a total of $5,000,000 and relinquishing the US claims on parts of Spanish Texas west of the Sabine River and other Spanish areas , under the terms of the Louisiana Purchase . 

Answer: answer: The Adams -- Onís Treaty of 1819 was a treaty between the United States and Spain in 1819 that ceded Florida to the U.S. and defined the boundary between the U.S. and New Spain.  It came in the midst of increasing tensions related to Spain's territorial boundaries in North America against the United States and Great Britain in the aftermath of the American Revolution.   Florida had become a burden to Spain, which could not afford to send settlers or garrisons.