Complex sentence: In 1828, Andrew Jackson was elected president, and he supported Indian removal, signing legislation by Congress in 1830, and sending US Army forces to remove the remnants of the Southeastern Indian tribes through the 1830s.
Split into simpler sentences: In 1828, Andrew Jackson was elected president, and he supported Indian removal, signing legislation to that effect by Congress in 1830. Later he used US Army forces to remove the remnants of the Southeastern Indian tribes through the 1830s.