As Secretary of State, Clay made trade agreements with newly independent Latin American countries. He sought to have the U.S. involved in the Pan-American Congress of 1826, but Congress approved the measure too late. Adams was not reelected for a second term and Clay returned to his home in Kentucky until he was elected to the Senate in 1831. Two years later he worked on the Compromise Tariff of 1833, which lowered tariffs gradually. Between 1832 and 1848, Clay ran for president four more times, but never succeeded. After losing the Whig Party nomination in 1848, he hoped to retire to his Ashland estate. But the following year he was once again elected to the U.S. Senate.