In 1819, Spain signed the Adams-Onis Treaty, ceding Florida to the United States and redefining the boundary between U.S. and Spanish territories from Louisiana to the Pacific Ocean.

President Donald Trump has refused to rule out military coercion to acquire Greenland and the Panama Canal, and he suggested making Canada the 51st state.

In 1819, the United States signed the Adams-Onís Treaty with Spain, which formally ceded control of East and West Florida. The treaty was ratified two years later. The United States did not pay ...