Which set of U.S. politicians were known as the "Great Triumvirate"?

John Calhoun, Daniel Webster and Henry Clay were known as the "Great Triumvirate" or the "Immortal Trio". These three would dominate U.S. politics for much of the first half of the 19th century. Each served in Congress and at various times held the post of U.S. Secretary of State. Calhoun also was vice president during John Quincy Adams' term and Andrew Jackson's first term. The three represented the major sections of the United States, Clay from Kentucky voiced the Western settlers, Webster from Massachusetts, the Northerner businessmen and Calhoun from South Carolina the Southern slaveholders.

The time these three served in the Senate together (starting in 1832 through 1850) witnessed the rising political pressure from slavery. Their debates lead to the Compromise of 1850 which delayed the problem of secession for another 10 years. John Calhoun died shortly after the Senate debate on the compromise, Webster and Clay would die within the next three years.