Le Sassier married Marie Francois Pauvert, in Saint-Domingue, then a French colony on the Caribbean island of Hispaniola (modern-day Haiti).
Mme Pauvert brought considerable property to the union as detailed in the marriage contract, dated May 13, 1783. Their son, Louis, was born in 1795. A daughter, Eugenie, died at birth in 1807.
In the Early Census of Louisiana, dated 1804, Le Sassier is listed as living in German Coast, Orleans Parish, an area heavily settled by Germans, but also by French and Arcadians. In the War of 1812, Le Sassier again signed up, at the age of 57, serving as a Sergeant in the 16th Regiment. His wife died February 12, 1829, and is buried in the Le Sassier family plot in the Metairie Cemetery, Orleans Parish.
In 1834, Le Sassier arrived in Texas, just as the impetus for the Texas Revolution was fomenting. Ever ready for a fight, in 1836, now 71, he enlisted in Major General Sam Houston’s army and fought in the Battle of San Jacinto on April 21. For this service he received one-third league of land (1,476 acres) plus an additional 320 acres. He died on January 8, 1837, in Columbia, Brazoria County, Texas, and was given a burial in that city befitting a hero of San Jacinto. Alexandre Le Sassier’s name is engraved on the Texas Society DAR Patriot Monument in the Texas State Cemetery, Austin, Texas.