Angus McNeill, land speculator and planter, was born in North Carolina in 1806. He was a resident of Natchez, Mississippi, on February 4, 1829, when he married Rebecca Jane Adams, daughter of Robert H. Adams, prominent Natchez lawyer and politician. In 1831 McNeill was one of three state commissioners negotiating the sale of state bonds to establish the Planters Bank of the State of Mississippi. On August 12, 1835, at Natchez, McNeill sold to Spurges Sprague and Robert J. Walker his interest in an undivided third of sixteen sitios of land that he, Jesse Perkins, and Walker had purchased at Nacogdoches, Texas, in January 1835. McNeill became acquainted with James Bowie in Mississippi in 1826. A manifest of Bowie's property, drawn up as part of a dowry contract signed by Bowie at San Antonio on April 22, 1831, included $20,000 held by McNeill for the purchase of textile machinery in Boston. In the fall of 1833, while lying ill at McNeill's home in Mississippi, Bowie learned of the deaths by cholera of his wife, their two infants, and his wife's parents in Monclova between September 5 and 8, 1833. McNeill moved to Texas in the company of Bowie and Dr. William Richardson in the late summer of 1835. His character certificate, dated September 7, 1835, at Nacogdoches, described him as married with family, was endorsed by A. Henrie, and noted his acceptance as a colonist in the Vehlein grant. McNeill received title to a sitio now in Liberty County on September 15, 1835. Diarist William Fairfax Gray, who met McNeill and his cousin, Maj. Alexander McNeill (also of Natchez), in Vicksburg on November 10, 1835, noted that McNeill had been a partner of J. J. Chewning in the failed firm of Wilkinson, McNeill, and Company, owned large amounts of land in Texas, where he had traveled extensively, and reputedly knew more of Texas than anyone else in Mississippi. At a public meeting held at the courthouse in Natchez on December 7, 1835, McNeill was appointed to a committee to make arrangements for a benefit to be given for "our former fellow citizens" serving militarily in Texas.
McNeill was a resident of Houston in 1837, when he became a charter member of the Philosophical Society of Texas. In the March 27, 1839, Telegraph and Texas Register, H. R. Allen ran a notice informing the public that he would not pay a note he had drawn up in favor of McNeill on December 12, 1837, because McNeill had failed to honor its terms. McNeill owned a sawmill in Houston when, in early 1840, he contracted to supply materials for a projected bridge to connect San Luis Island to the mainland. After Adrián Woll's campaign, McNeill equipped himself for military service and rode with a party of companions as far as Gonzales before they ascertained that the Mexicans had retreated. McNeill moved to Colorado County in 1844. At Columbus on May 18, 1846, he joined the military for a six-month term and served as a private in Capt. Claibourn C. Hebert's company (E) of the First Regiment, Texas Mounted Rifles, which mustered into federal service at Point Isabel on June 7, 1846. He was discharged at Camargo, sometime before his company mustered out at Monterrey on October 2. At Columbus on July 31, 1849, he was appointed to represent Colorado County at the Memphis Railroad Convention to advocate construction of a southern railroad from the Pacific. During the Civil War he served as a private in Capt. Thomas S. Anderson's company of Eagle Lake, Texas State Troops, Twenty-second Brigade. Colorado County federal census schedules indicate that McNeill had three children. He died at Eagle Lake on June 20, 1882. His obituary and Gray's diary reveal that he was a much-liked, visionary man of considerable intelligence, some eccentricities, and few faults. He was a cousin of early Texan Henry C. McNeill.