What was president theodore roosevelt’s square deal

The Square Deal was President Theodore Roosevelt's domestic program.

Explanation:

Roosevelt's Square Deal quickly began to implement progressive ideas in the country. Domestically, it strengthened the workers and campaigned massively for control over monopolistic commercial companies; President Roosevelt even filed a state suit against the railroad trust led by J. P. Morgan.

Its reforms also concerned administrative structures (for example, attempts to establish an independent civil service), the economy and environmental policy. In doing so, President Roosevelt primarily opposed those who got rich at the expense of the workers, and thus went on a confrontation course with most of the members of his own party.

The prominent figure that opposed the Mexican-American War was  (C) Henry Clay.

Henry Clay was a U.S. congressman and a presidential candidate that was also called the "Great Pacificator". He was against the annexatiation of Texas because it meant to risk the integrity of the Union; however, after some time, he decided that he was willing to support the annexation if this was achieved without a war. Therefore, in contrast to James Polk, who had an expansionist agenda, Henry Clay opposed the Mexican-American War. The declaration of war was finally approved by the U.S. Congress on May 13, 1846.