Question: The Territory of Florida was ceded to the United states as part of a treaty between which two countries ?

Context paragraphs:
Treaty of Dappes: The Treaty of Dappes was concluded on 8 December 1862 between France and the Swiss Confederation.  Resolving a long-standing border dispute between the two countries, the accord awarded the Vallee des Dappes (which had been controlled by Switzerland since 1815) to France, in exchange for a comparable piece of territory just to the north.  The treaty is noteworthy for dividing the tiny village of La Cure between the two countries, with the new border bisecting not just the town itself, but several structures within it.

Adams–Onís Treaty: 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; and also 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.

Treaty of Fort Clark: The Treaty of Fort Clark (also known as the Treaty with the Osage or the Osage Treaty) was signed at Fort Osage (then called Fort Clark) on November 10, 1808 (ratified on April 28, 1810) in which the Osage Nation ceded all the land east of the fort in Missouri and Arkansas north of the Arkansas River to the United States.  The Fort Clark treaty and the Treaty of St. Louis in which the Sac (tribe) and Fox (tribe) ceded northeastern Missouri along with northern Illinois and southern Wisconsin were the first two major treaties in the newly acquired Louisiana Purchase.  The affected tribes, upset with the terms, were to side with the British in the War of 1812.  Following the settlement of that war, John C. Sullivan for the United States was to survey the ceded land in 1816 (adjusting it 23 miles westward to the mouth of the Kansas River to create the Indian Boundary Line west of which and south of which virtually all tribes were to be removed in the Indian Removal Act in 1830.

Florida Territory: The Territory of Florida was an organized incorporated territory of the United States that existed from March 30, 1822, until March 3, 1845, when it was admitted to the Union as the State of Florida.  Originally the Spanish territory of "La Florida", and later the provinces of East and West Florida, it was ceded to the United States as part of the 1819 Adams–Onís Treaty.  It was governed by the Florida Territorial Council.

Treaty of Ghent: The Treaty of Ghent (8 Stat.  218 ) was the peace treaty that ended the War of 1812 between the United States of America and the United Kingdom of Great Britain and Ireland.  Both sides signed it on December 24, 1814, in the city of Ghent, Belgium.  The treaty restored relations between the two nations to "status quo ante bellum", restoring the borders of the two countries to the lines before the war started in June 1812.  The Treaty was approved by the UK parliament and signed into law by the Prince Regent (the future King George IV) on December 30, 1814.  It took a month for news of the peace treaty to reach the United States, and in the meantime American forces under Andrew Jackson won the Battle of New Orleans on January 8, 1815.  The Treaty of Ghent was not fully in effect until it was ratified by the U.S. Senate unanimously on February 17, 1815.  It began two centuries of peaceful relations between the U.S. and Britain, although there were a few tense moments such as the Trent Affair.

Osage Treaty (1825): The Osage Treaty (also known as the Treaty with the Osage) was signed in what became Council Grove, Kansas, on June 2, 1825 between William Clark on behalf of the United States and members of the Osage Nation.  The accord contained fourteen articles.  Based on the most important terms of the accord, the Osage ceded multiple territories to the United States government.  According to the first article of the treaty, the territories ceded entailed lands lying within and west of both the State of Missouri and the Territory of Arkansas, lands lying north and west of the Red River, all territories south and east of the Kansas River, and all lands located through the Rock Saline.  The accord was proclaimed on December 30, 1825.

Chieftains Museum (Major Ridge Home): Chieftains Museum, also known as the Major Ridge Home, is a two-story white frame house built around a log house of 1792 in Cherokee country (today it is within present-day Rome, Georgia).  It was the home of the Cherokee leader Major Ridge— notable for his role in negotiating and signing the Treaty of New Echota of 1835, which ceded the remainder of Cherokee lands in the Southeast to the United States.  He was part of a minority group known as the Treaty Party, who believed that relocation was inevitable and wanted to negotiate the best deal with the United States for their people.  The chiefs had agreed they could not go to war against the United States on the removal issue, but most other Cherokee opposed Ridge and the Treaty Party.  He and some other members of the Treaty Party were murdered after removal to the Cherokee Nation in Indian Territory for having ceded the tribe's communal lands, as this was considered a capital crime.

Battle of Fallen Timbers: The Battle of Fallen Timbers (August 20, 1794) was the final battle of the Northwest Indian War, a struggle between Native American tribes affiliated with the Western Confederacy, including support from the British led by Captain Alexander McKillop, against the United States for control of the Northwest Territory (an area north of the Ohio River, east of the Mississippi River, and southwest of the Great Lakes).  This land had been ceded to the United States in accordance with the Treaty of Paris (1783), but the Native Americans (who had not been party to the treaty) refused to comply with the treaty and relinquish control.  British army bases were maintained there to support their Native allies.  This ultimately led to the American offensive and subsequent British-Indian withdrawal from the territory altogether following the Treaty of Greenville.  The battle, which was a decisive victory for the United States, ended major hostilities in the region until Tecumseh's War and the Battle of Tippecanoe in 1811.

Treaty of Old Crossing: By the Treaty of Old Crossing (1863) and the Treaty of Old Crossing (1864), the Pembina and Red Lake bands of the Ojibwe, then known as Chippewa Indians, purportedly ceded to the United States all of their rights to the Red River Valley.  On the Minnesota side, the ceded territory included all lands lying west of a line running generally southwest from the Lake of the Woods to Thief Lake, about 30 mi west of Red Lake, and then angling southeast to the headwaters of the Wild Rice River near the low-lying divide separating the watershed of the Red River of the North from the watershed of the Mississippi River.  On the North Dakota side, the ceded territory included all of the Red River Valley north of the Sheyenne River.  The total land area, roughly 127 mi wide east to west and 188 mi long north to south, consisted of nearly 11000000 acre of rich prairie land and forests.

Brazil–United States Treaty: The Brazil–United States Treaty was a military assistance agreement signed in 1952 in Rio de Janeiro between the two countries, with the goal of defending the Western Hemisphere.  Military relations between the United States and Brazil date back to World War II, when Brazil supported the Allied effort in the invasion of Italy in 1942.  Brazil provided troops for the invasion.  On January 3, 1952, The Brazilian government issued decree 30363 establishing new government regulations.  These new regulations allowed for the return of foreign capital that was invested in Brazil and profit remittances on that capital.  Shortly after, representatives from the United States and representatives from Brazil started to negotiate a bilateral military assistance agreement in Rio de Janeiro on January 3, 1952.  The document outlining the agreement between the two countries would be signed on March 15, 1952.  The agreement went into effect on May 19, 1952.  During the time of the negotiations, Major General Charles L. Mullins, Jr. negotiated a separate military plan with the Brazilian Government.  The plan was approved on March 14, 1952 by the Secretary of Defense Lovett.  In a private ceremony on March 15, 1952 United States Major General Mullins and Brazilian General Monteiro signed the military plan that outlined a common defense between the two nations.  The agreement allowed major weapons and training by the United States military to the Brazilian military.  This tenuous alliance governed the two nations bilateral ties during the events of the Cold War.  However, the alliance was short lived, and suffered several major blows between the two nations during the military coup in Brazil in 1964.  During this time the United States still provided military support and training to the side that supported the United States.

Supporting paragraphs: Florida Territory Adams–Onís Treaty
Answer: the United States and Spain