James Winwright Flanagan, Texas lieutenant governor and United States senator, was born in Gordonsville, Albemarle County, Virginia, on September 7, 1805, the son of Charles and Elizabeth (Saunders) Flanagan. In 1815 the family moved to Boonesboro, Kentucky, where James received a rudimentary education. As a young man he traded in horses and mules in eastern Kentucky and western Virginia before entering the mercantile trade at Cloverport, Kentucky. He was successful enough that he soon owned a flotilla of flatboats that he sent down the Ohio and Mississippi rivers as far as New Orleans to sell local produce. In 1826 at Cloverport he married Polly Miller Moorman. The couple had five children, including David Webster Flanagan, who became a prominent Republican politician in Reconstruction Texas. Flanagan served for twelve years as justice of the peace at Cloverport and in 1833–34 was a member of the circuit court of Breckenridge County.
In 1843 he moved to Texas and settled in a community called Slabtown, near the Louisiana border, where he established himself as a farmer and merchant. On August 9, 1844, he moved to Henderson, where he opened a store, farmed, speculated in land, and practiced law. His wife, Polly, died in 1844 at Henderson, and sometime after 1850 Flanagan married a widow named Elizabeth Ware. By 1850 he had amassed $14,856 worth of real estate.
A Whig in the 1830s and 1840s and thereafter a staunch Republican, Flanagan was a close friend and supporter of Sam Houston. In 1851–52 he served in the Texas House of Representatives and in 1855–58 in the Texas Senate. While in the state legislature he was a strong advocate of a state asylum for the insane and favored such causes as government-supported railroads. In 1856 he was a presidential elector, and in 1860 he was elected a delegate to the Peace Conference called by Houston. During the Civil War Flanagan, ever a strong Unionist, retired to his farm and produced leather on contract for the Confederate States Army.
He was a delegate to the Constitutional Convention of 1866, but the document produced by this convention was rejected by the federal government, and congressional Reconstruction was instead imposed upon the state. Flanagan was a delegate to the Texas Constitutional Convention of 1868–69, this time with his son, Webster. When the new constitution was approved by the federal government, Flanagan was elected lieutenant governor in 1869 under Edmund J. Davis, and his son was elected to the state Senate. When the elder Flanagan vacated the position later that year, having been elected by the legislature to the United States House of Representatives as an at-large representative, his son replaced him as president pro tem of the Senate. The next year the legislature sent Flanagan to the United States Senate, where he served from March 30, 1870, until March 3, 1875, when he was succeeded by Samuel Bell Maxey. In Congress and in the Senate Flanagan supported Ulysses S. Grant and his administration. He was appointed chairman of the Committee on Post Offices and Roads, the Committee on Education, and the Committee on Labor. On March 7, 1872, he delivered a speech to the Senate in support of his proposal to alienate to the federal government all of Texas north and west of a line drawn from the northwest corner of Hardeman County to the mouth of the Pecos River. This land, more than a third of the state, was to be designated an Indian reservation.
Upon leaving the Senate, Flanagan retired to his farm at Longview. His third marriage was to Elizabeth Lane. He had a total of eleven children. He died at Longview on September 19, 1887, and is buried in Henderson beside his first wife. He was a Baptist and an Odd Fellow. Some of his papers are preserved in the James Wainwright Flanagan collection Barker Texas History Center, University of Texas at Austin.