In 1870 Luke Brennan age 50, his wife Mary age 40 and their children Mary 16, Edward 15, Denis 13 and Ellen 3 are recorded living in Charleston. Luke Brennan was a wheelwright.
City Directories for Charleston 1874 and 1887 record Luke Brennan as a wheelwright.
In 1880, Mary Brennan LaFourcade age 26 was living with her husband Francis age 30, and their children, May age 3 and Edward age 1, and her father Luke Brennan age 60, his wife Mary and their sons Edward and James? in Charleston, South Carolina. Luke Brennan and his wife Mary are both recorded as being born in Ireland. All the others are recorded as having been born in South Carolina. Francis LaFourcade's parents were both born in France. Luke Brennan was a wheelwright. The household also had a servant Annie Beard of South Carolina.
By 1900, Francis Lafourcade, Fireman Locomotive, was the head of the household. He was living with his wife Mary (Brennan) and their children, Mary 27, Edward 29, Harry 30, Frankie 13, Ethel 7 and Leona 3. Luke and Mary Brennan are also living with them although Luke is recorded as Francis' brother in law! Luke gave his date of birth as Jan. 1815. He stated that he came to the U.S. in 1825 and has been a resident of the U.S. for 75 years. He also stated that he was a Naturalised Citizen. Mary Brennan gave her date of birth as Feb. 1820. The entries tell us that Mary had been married for 50 years and sadly that though she gave birth to 10 children, only 1 is still living. She came to the U. S. in 1840 so had been resident in the U.S. for 60 years.
On Feb. 18, 1926, the death of Mrs. Mary A. LaFourcade, Widow, was recorded in Charleston by (her daughter?) Miss LaFourcade of 4B Warren Street. Mary LaFourcade's parents are recorded as Luke Brennan, Ireland and Mary Brophy, Ireland. Mary Brennan LaFourcade is buried in St. Laurence Cemetary, South Carolina.
If the details found here are accurate Luke Brennan of Charleston is not my great great granduncle. This Luke arrived in the U.S. in 1825 as a boy of 10 years and his wife was Mary Brophy.
Sources; Original Census Records 1870, 1880, 1900 and Death Certificate available online