Which Union general became the 18th President?

Which president signed the Indian Removal Act of 1830, leading to the Trail of Tears? Which president led the U.S. during the Mexican-American War? Which president issued the Emancipation Proclamation? In what year did Abraham Lincoln deliver the Gettysburg Address? Which president led the "Rough Riders" during the Spanish-American War before becoming president? Which president is the teddy bear named after? Which president championed the building of the Panama Canal? Which president proposed the League of Nations after World War I?