After serving as colonial magistrate, he returned to England in 1856 and later was promoted to captain and served as a British Member of Parliament for Portsmouth. The Crossman River, a  tributary of the Hotham River, was most likely named by Gregory in 1853.
After serving as a colonial magistrate, he returned to England in 1856 and later became captain and represented Portsmouth in parliament. It is likely that Gregory named the Crossman River in 1853.