At 16, while working at a passport office, he learned he was going to be drafted into military service. Not wishing to be conscripted, Sterne forged a passport for himself and fled to the United States. He immigrated to New Orleans then worked in the mercantile trade and studied law. He also joined the Masonic Lodge.
In 1826, Sterne established a mercantile house in Nacogdoches, Texas. He soon became involved in the Fredonian Rebellion and helped Hayden Edwards and others in their resistance against the Mexican government. One of Sterne's tactics was to smuggle guns, flints and lead in barrels of coffee and other dry goods.
Eventually, spies discovered Sterne's activities and he was arrested. He was tried for treason and sentenced to be shot. He was soon pardoned and released on the vow that he would not undertake arms against the government.
In 1832 Sterne fought with the Texians in the Battle of Nacogdoches, where they pursued Mexicans fleeing across the border. Although he did not carry a gun, he piloted the troops and acted as a company lookout.
In 1835, Sterne assembled and financed a company called the New Orleans Grays, who fought bravely against the Mexicans.
In 1839, during the Cherokee War, Sterne captained a company of volunteers. They were victorious against the Cherokees during the Battle of Neches, on July 16, 1839. Many men were wounded and killed on both sides, including the Cherokee grand chief, Bowls, who was killed and Sterne himself, who was wounded. This was effectively the last major battle of the Cherokee wars.
Later on he served in several official capacities, as Postmaster, associate justice of the county court and justice of the peace. He also represented Nacogdoches in the House of Representatives.
He died in New Orleans in 1852.