Following his convalescence, Hardy agreed to a cousin's proposal to start Sylvarena Academy,[2] a boys' primary school affiliated with the Methodist Church.

In 1859, he met, and in 1860, he married Sallie Ann Johnson, with whom he had six children (Mattie, Willie, Ellen, Elizabeth, Thomas, and Jefferson Davis) before her death in 1872.

He later became General Counsel for the company, although his legacy with that railroad centers on two things in particular: Hardy's engineering work to construct the bridge spanning Lake Pontchartrain and his efforts to secure funding once the road went into receivership during the economic Panic of 1873.

[6] Hardy's increasing involvement in the day-to-day operations of the NO&NERR, eventually as that road's General Counsel, necessitated a move to Meridian, Mississippi in 1873.

[8] Throughout his long involvement with the Gulf and Ship Island, Hardy lobbied investors and financiers throughout the north, west, and Europe to bring their capital to his project; eventually, the reality of Reconstruction economics got the best of him.

The final blow came with a financial collapse; Hardy's efforts to secure financing could not counter a wholesale panic, and the Gulf and Ship Island went into receivership in 1896.