Chichester Chaplin, jurist in Texas and Louisiana, was born in Ireland on November 17, 1800. He probably immigrated to southeastern Louisiana between 1810 and 1820. Marriage records of St. Tammany Parish reveal his marriage on October 10, 1824, to Tabitha Beall Edwards Aydelot, daughter of empresario Haden Edwards. Chaplin was then a fledgling lawyer. Tabitha died on November 24, 1827. Chaplin undoubtedly followed his father-in-law to the Nacogdoches area of East Texas, where he became a key figure in the Fredonian Rebellion (1826), led by Haden and Benjamin W. Edwards, along with Martin Parmer, who later became Chaplin's second father-in-law. Edwards ordered an election held on January 1, 1826, to select an alcalde for the Nacogdoches District. Chaplin actually received the most votes, but the losing candidate, Samuel Norris, an American who had married a Spanish colonial woman and was the choice of the old settlers, appealed the election to the political chief of Texas, who declared Norris the legally elected candidate.
When the Fredonian Rebellion erupted in December 1826, Chaplin joined the Edwards forces in revolt, and when the rebellion collapsed he fled eastward across the Sabine River with the Edwards brothers and Parmer. The Chaplin family settled in Natchitoches, where, on June 4, 1827, Chaplin was named a justice of the peace for Natchitoches Parish, a post he held for less than a year. With his selection as a Louisiana justice in 1827, he began a judicial career in both western Louisiana and eastern Texas that spanned almost four decades (1827–64). In 1827–28 he served as probate judge and from 1829 to 1834 as parish judge of Claiborne Parish, Louisiana, newly formed from a portion of the original Natchitoches Parish.
Sometime late in 1833 or early in 1834 he returned to Jefferson County, Texas, where in 1836 he was chosen the first chief justice of the county. He served in that office for a short time and in 1838 was made a member of the Board of Land Commissioners of San Augustine County, Texas. Since he was in Texas before 1835, Judge Chaplin was awarded a Mexican land grant of a league in San Augustine County, on May 18, 1835. In December 1839 he received a headright grant of 640 acres in Jasper County from the Republic of Texas. In 1840 he purchased land from the Parmers, his wife's family.
By 1845, however, he was again in Louisiana serving as district attorney for Sabine Parish, a post he held until 1853, when he was installed as district judge of the parish. When a district court for the Sixteenth District was established in 1855, he began functioning as judge of both the old Ninth District Court and the new Sixteenth District Court, both headquartered in Sabine Parish; he held this dual post until December 1864. In 1865 Chaplin completed his public service as the attorney for the Natchitoches Parish police jury.
While he was a fugitive from the Fredonian Rebellion, Chaplin married his second wife, Emily Parmer. This marriage must have occurred in 1829 or 1830, probably in Natchitoches Parish. They had six children. In 1870 Chaplin was grand master of Phoenix Lodge No. 38 in Natchitoches. He died on October 14, 1874, and Emily died on August 9, 1878. Both are buried in the American Cemetery in Natchitoches.