Born in Prairie du Chien, Michigan Territory, his father was the fur trapper Jean-Baptiste Faribault.

Alexander contributed the land and a large sum of money for the construction of the first Catholic Church, St. Ann in 1856.

Alexander made a larger financial contribution to build a fireproof stone church on the same site as St. Ann in 1858.

"[5] After most Dakota were ordered into exile from their Minnesota homelands in 1863, Faribault sheltered a number of Wahpekute and Mdewakanton people on his farm.

[6] His son-in-law was William Henry Forbes, who also served in the Minnesota Territorial Legislature.