The excerpt describes the federal government policy established by which landmark executive action?

The Louisiana Purchase was a land acquisition that doubled the size of the United States but did not specifically address the issue of European colonization of the Americas. This treaty primarily involved the acquisition of territory from France and did not establish a foreign policy principle regarding European powers.

The Adams-Onis Treaty, also known as the Transcontinental Treaty, resolved territorial disputes between the U.S. and Spain, including the acquisition of Florida. While it involved territorial expansion, it did not encompass the broader principle of preventing European colonization in the Americas as articulated in the Monroe Doctrine.

The Treaty of Guadalupe-Hidalgo ended the Mexican-American War and resulted in significant territorial gains for the United States. While it expanded U.S. territory, it did not establish a policy regarding European colonization or intervention in the Americas, which is the focus of the Monroe Doctrine.