He served in the Royal Navy for eight years, attaining the rank of lieutenant, before his career was cut short due to rheumatic issues.

[1] Continuing his service in the Royal Navy, by the end of 1746 Gresley was serving in the 24-gun frigate HMS Bridgewater, a prison ship stationed in the Firth of Forth, as a volunteer.

In 1765 he and his family moved from Knypersley to Worcester both to allow his children better access to education and to help Gresley lessen the weight of some debts, accrued from business ventures.

3. c. 16) was passed allowing Gresley and his son to build a private canal from Apedale to Newcastle-under-Lyme so that he could more easily transport the mine's products of coal and ironstone.

[10][11] Mostly built on land already owned by Gresley, the project was profit-driven but also resulted in the price of coal being set at the same rate until the expiration of the act, greatly to the benefit of the local public.

[1][13] He was eulogised by Philip Thicknesse, who wrote that Gresley was "a kind husband, a tender father, a zealous friend, an hospitable neighbour.