On May 13, 1846, the U.S. Congress declared war on Mexico. Behind the scenes? Land lust, slave politics, and a president with a map in one hand and a match in the other.

In the early 1800s, America changed from a land of small farms to a booming nation of factories, railroads, and markets. The Market Revolution connected people, goods, and ideas—while also revealing deep inequalities in who benefited from progress.

The Great Society wasn’t just a policy agenda, it was a radical vision of what America could be. With sweeping reforms in health care, education, civil rights, immigration, and the environment, President Johnson’s plan aimed to eliminate poverty and racial injustice once and for all.