Leonidas (Lon) Carrington Hill, Sr., South Texas developer, the son of Maj. William H. and Minerva Frances (Vernon) Hill, was born on Gilleland Creek in Travis County, Texas, on July 31, 1862. He attended Rock Church School, Parson's Seminary Episcopal School near Manor, and Add-Ran Male and Female College. Hill married Eustacia Dabney on December 13, 1882. After managing a general store in Manor, he studied law and moved to Austin to attend the law school at the University of Texas. He also attended the University of Virginia, where he received his license to practice law in that state on September 1, 1890; he was licensed for practice in Texas on March 13, 1891. In April of that year Hill and his family moved to Beeville, where he practiced law for twelve years. On June 20, 1896, the Bee County Democrats endorsed Hill for district attorney. He was serving in that position as late as 1899, by which time he was considered one of the Democratic party leaders of the county.
Hill was first introduced to the lower Rio Grande valley while traveling from Alice to Brownsville. He became interested in developing the area and started purchasing land in Cameron County. He started a rice plantation in the Brownsville area, ran the Miller Hotel, and platted Six Shooter Junction. He continued to practice law in Bee County through 1902, while his rice plantation remained under the management of Elmo Coleman. Between August 1901 and November 1902 Hill acquired 300,000 acres in the Hidalgo-Cameron County area. The city of Harlingen, which he founded, was located on land that had been Cameron County school lands, Texas school lands, and part of the King Ranch. He paid $2.50 an acre for the King Ranch property he purchased from Mrs. Henrietta King. On June 6, 1903, Hill called a mass meeting in Brownsville to propose the construction of a railroad; he subsequently headed the soliciting committee to raise the bonus for the road. On June 10, 1903, Mrs. Hill and their eleven children joined him in Cameron County, first at Point Isabel and then at Brownsville. At that time Hill was operating a hardware and implement store in Brownsville. A year later, when the Gulf Coast lines reached the clearing that was to be Harlingen, he was one of the three men who guaranteed the bonus for an extension of the Sam Fordyce branch to the Starr county line. On August 10, 1903, he chartered the Lon C. Hill Improvement Company, which became the Lon C. Hill Town and Improvement Company in 1904. Eustacia and her youngest child died in 1904 of typhoid fever.
In 1904 Hill chartered the Capisallo Town and Improvement Company, which laid out the town of Lonsboro. It was later sold to the American Rio Grande Land and Irrigation Company and renamed Mercedes. That same year Hill was one of the incorporators of McAllen. He and others chartered the Harlingen Land and Water Company for $300,000 in 1907. By November 15, 1907, he certified that the company was operating twenty-six miles of canals and that 75,000 acres was under irrigation or being prepared for it. The Hill Sugar Mill was in operation in Harlingen by November 1911. Hill participated in passing the original state law governing irrigation districts, and on August 10, 1914, Cameron County Irrigation District No. 1 was established.
Hill was often called "the Chief" because of his height and his heavy, shoulder-length hair. During the early 1900s he met Rex Beach, who chose to use Hill as the model for the main character in his novel Heart of the Sunset (1915). In 1915 Hill received orders from the Texas Rangers to be a border scout so that he might fight off Mexican bandits. About that time he befriended William Jennings Bryan and sold him some land in South Texas. The Hill Sugar Mill was burned down by bandits on July 17, 1917.
During World War I Hill served as a "dollar a year man" in Washington, D.C. He continued his land and water development until his death at Harlingen on May 5, 1935. Lon C. Hill Park was dedicated in 1950 and was designated a state historical landmark in 1962. In the early 1990s Hill's home was a museum in Harlingen.