Why did John Quincy Adams oppose a joint U.S.-British declaration on colonization in the Americas?

John Quincy Adams opposed a joint U.S.-British declaration regarding colonization in the Americas because he feared that a bilateral agreement would hinder the United States' own expansionist designs.12

While British foreign minister George Canning proposed a joint statement to prevent European powers from recolonizing newly independent nations in Latin America, Adams argued that the United States should instead issue a unilateral declaration of its own policy. He believed it was essential to "make an American cause" and adhere to it independently, rather than appearing as a junior partner to Britain or limiting American freedom of action in the Western Hemisphere.12

Ultimately, President James Monroe sided with Adams, leading to the issuance of a unilateral statement that would later become known as the Monroe Doctrine.12