Doug Wells comments:
We recovered several stamped bricks from a 19th c. sugar mill on the Mississippi River opposite New Orleans last year. Two of them are standard building bricks, stamped with the single letters, "H" or "M". The third is a fire brick marked "T A and Sons." We recovered one of these "T A" bricks a few years back from a well in Natchez that had been sealed in 1867. Any ideas on their origins?