Shipbuilding and merchant fleet
Southard built his first ship—a schooner named Texas—before the age of 29 (in about 1837). He then designed a series of small "coasters" intended for the Southern coastal trade, with names such as Savannah, Richmond and Wilmington. According to Little's Genealogy, Southard then formed a partnership with a talented young shipbuilder named Stanwood Alexander; the two of them building sixteen ships together from 1845 until Alexander's death in 1852. Southard then continued as a sole trader, operating the business under the name T. J. Southard & Co..
In 1865, Southard's son Charles H. T. J. Southard became a partner in the firm, after which it usually traded as T. J. Southard & Son, although at least two ships were constructed under the name of T. J. & C. H. Southard. According to his own testimony, Charles' main role in the firm was bookkeeping, although he is also later said to have assisted in the management of his father's merchant fleet.
Over the course of some 44 years, the Southard shipyard built between 75 and 100 wooden-hulled sailing ships of all kinds, large and small, including schooners, barks, brigs and full-rigged ships, his vessels having "an industry-wide reputation for reliability of workmanship and trimness of line." T. J. Southard owned shares in many of the ships he built, and was the first local shipbuilder to own 100% of a ship (the ship's captain in this era usually being obliged to own at least one-sixteenth of his command). By these means, Southard became not only a shipbuilder but the head of his own merchant fleet, his ships flying the Southard house flag with a design incorporating an anvil—a pictorial reference to the proprietor's smithing origins.
An early vessel of note built by Southard was Buena Vista, a 660-ton vessel built in 1848 which, though not a clipper, had a reputation for speed, sometimes clocking passages comparable with clippers and once making a "splendid passage" of 60 days from San Francisco to Calcutta. In 1853, Southard built the 1,854-ton ship Gauntlet, which for many years retained the distinction of being the largest ship ever built in Maine. Sold to the British in 1860 and renamed Sunda, the vessel under Captain "Bully" Bragg subsequently made a number of very fast passages, including a record 76-day passage from London to Brisbane. In 1854, Southard built the 1,400-ton Wizard King, which "established for itself a fine record in Australian service." Both Gauntlet and Wizard King were classified as clippers and are usually referred to as such, but according to Fairburn, were no more than "half-clippers" at best.
Some of the largest vessels built at the Southard yard, constructed between 1875 and 1879, were the full-rigged ships Charles Dennis—"a good-looking and loftily-spired ship" of 1,710 tons; Eureka (2,101 tons); Red Cross (1,300 tons) and Theodore H. Allen (1,537 tons). Of these, Eureka in particular was an "outstanding" ship: the largest Maine-built vessel at time of construction, she later made several fast passages around Cape Horn or across the Atlantic. The largest vessel built by Southard—and apparently the largest ever built in the state north of Bath—was Commodore T. H. Allen, a vessel of 2,390 tons and 245 feet in length, built in 1884, which is also known to have recorded some respectable times. According to the Southard family itself, the last vessel built by the Southards was a four-masted schooner named Edith L. Allen, completed in 1890.
One of Southard's ships, Ellen Southard, is best known for the manner of her demise, as it led to a change in U.S. law. The vessel was wrecked in 1875 with the loss of nine lives in a gale near the mouth of the Mersey River, Liverpool. The courage of British lifesavers attempting a rescue prompted the United States Congress to alter the statute covering Lifesaving Medals to allow them to be awarded for the first time to non-Americans. A total of 27 Lifesaving Medals were awarded over the Ellen Southard disaster.