By the late 1840s, the Cooper family were still living in Skipton. Of the twelve children born to Christopher and Sarah, only seven were still living. In 1849, Thomas married Ann Laycock Brown, the daughter of retired innkeeper William Brown, in the Western Chapel in Skipton. Their first son, William was born in Skipton in 1850.
With his pregnant wife Ann and their two children, Thomas set sail from Plymouth aboard the SS Omega on 29th May 1852. Because he was a tradesman, Thomas paid 11 pounds for the passage out, a labourer paid only 1 pound under the emigration scheme of the colonial commissioners. The voyage took 86 days, and the Omega arrived in Port Adelaide on the 24th of August. A busy scene greeted the Coopers, as there were a number of ships in port disembarking passengers, unloading goods, and bringing eagerly awaited news from England and other colonies for the 33,000 inhabitants of the city.