A new documentary series from Kevin Costner will offer 'diverse perspectives' on stories of America's westward expansion.

Worth, during the Mexican-American War.1855. Library of Congress. In 1844, President James K. Polk ran on a Democratic platform that supported manifest destiny, the idea that Americans were ...

The outcome of the Spanish-American War left the US with a new-found degree of global power and influence. It also presented a dilemma of sorts for President William McKinley. The 1898 Treaty of ...