First Chairman of Democratic Party. He received notoriety as a Massachusetts lawyer and Democratic Political Party activist, who became the first chairman of the Democratic National Committee. He graduated from Brown University in Rhode Island in 1816, then studied law and as an eloquent writer, began a journalistic career in Providence, Rhode Island. He expressed anti-slavery viewpoints. Relocating to Boston, Massachusetts, he accepted a position with the “Boston Advocate,” and when the “Boston Advocate” merged into the “Boston Post,” he became head of one of the New England's most Democratic newspapers. In 1827, he was with the “Boston Daily Advertiser.” He became a prominent member of the Suffolk County, Massachusetts bar. At first, he supported the views of the Anti-Masonic Party before switching to the Democratic Party. In 1832 he published the results a December 7, 1831 and January 7, 1832 investigation as the “A Legislative Investigation in the Masonry; Being a correct history of the examination under civil oath.” He did not support the views of Henry Clay. He was a candidate for the United States Congress in 1844 and again 1848 being defeated each time. In 1848 until 1852, he became the first Chairman of the Democratic National Committee. In 1849 he argued before the United States Supreme Court the case “Luther v. Borden in support of Rhode Island's Dorr's Rebellion and increasing the citizen's voting rights by a republican government. In March of 1853, Hallett was appointed by United States President Franklin Pierce to a four-year term as United States District Attorney for the District of Massachusetts. He supported President James Buchanan's “Dred Scott Decision.” At the 1856, Democratic National Convention, he was the chairman of the Platform Committee. He married Laura Larned and the couple were the parents of a daughter and a son. He missed the 1860 Democratic Convention as his wife was dying and since his health was declining and dying two years later, he never was elected again to serve. He taught many promising law students including one of his last students, John Howard Ferguson. Many of his speeches, such as the “1836 4th of July Oration” and the “Rights of the Marshpee Indians,” and court cases, such as murder cases, have been documented in textbooks becoming collector's items. His biography was printed in William Thomas Davis' 1895 “Bench and Bar of the Commonwealth of Massachusetts” and Keith Medley's 2003, “We Freemen: Plessy v. Ferguson.”