Roosevelt reshaped the federal government's role in the economy through the New Deal, creating programs and institutions such as Social Security, the FDIC, and large-scale public works to relieve unemployment and stabilize finance.
He also guided the United States through World War II, overseeing mobilization, Lend-Lease, and Allied cooperation; his four-term presidency expanded the scope and influence of the executive branch and left a lasting global and domestic legacy, though some initiatives, like the 1937 court-packing plan, provoked controversy.