After the Mexican-American War concluded, which of the following events occurred?

A The United States purchased the Oregon
Territory

from Britain.

B The United States invaded Mexico once more.

C The Wilmot Proviso was
passed in Congress.

D The United States stretched from the Atlantic to
the Pacific Ocean.

D.

Explanation:

Mexican-American began on April 25, 1846, with an attack by Mexican soldiers over the United States military in the disputed land. This attack claimed dozens of US soldiers' lives.

The war lasted till 2nd February 1848 and came to an end with the Treaty of Guadalupe Hidalgo. With this treaty, the United States was able to expand its territory from the Atlantic to the Pacific Ocean.

Therefore, option D is correct.

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