The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
The United States embraced imperial expansion in the late 1800s and early 1900s by exerting the foreign policy derived from the Monroe Doctrine and strengthened with the "Big Stick" foreign policy implemented by United States President Theodore Roosevelt.
After the Indian Wars, the United States federal government participated in many wars that included expansionists ideas, as was the case of the Mexican-American War, the Spanish-American War, and the U.S.-Philippines War.