What do we call the largest phase of imperialism in us history

Explanation:

American imperialism comprises policies aimed at extending the political, economic, and cultural influence of the United States over areas beyond its boundaries. Depending on the commentator, it may include military conquest, gunboat diplomacy, unequal treaties, subsidization of preferred factions, economic penetration through private companies followed by intervention when those interests are threatened, or regime change.[4][page needed]

The policy of imperialism is usually considered to have begun in the late 19th century.[5] The federal government of the United States has never referred to its territories as an empire, but some commentators refer to it as such, including Max Boot, Arthur Schlesinger, and Niall Ferguson.[6] The United States has also been accused of neocolonialism, sometimes defined as a modern form of hegemony, which uses economic rather than military power, and sometimes used as a synonym for contemporary imperialism.

the reform movements that arose during the antebellum period in america focused on specific issues: temperance, abolishing imprisonment for debt, pacifism, antislavery, abolishing capital punishment, amelioration of prison conditions (with prison's purpose reconceived as rehabilitation rather than punishment), the humane treatment of animals, the humane and just treatment of native americans, the establishment of public institutions for the care of the destitute, orphans, blind, and mentally ill, the establishment of public schools, the abolition of tobacco use, vegetarianism, health reform, homeopathic medicine, woman's rights (including, at first, especially the establishment of a woman's right to own property apart from her husband and her right to sue for divorce), and the amelioration of labor conditions (including higher pay, the right to form unions, the right to strike, and the demand for limits on the number of work hours, and safe working conditions).

explanation:

1 wagon is the right answer