Johann (John) Jacob Groos, surveyor and commissioner of the General Land Office, was born in Offenbach, Germany, in 1822. Groos had three years of college study as a civil engineer and worked as a surveyor in Germany. In 1845 he married Katharine Blieder, with whom he had five sons and two daughters. Groos became interested in accounts of Texas circulated in Germany by agents of the Adelsverein, and in 1845 he immigrated to Texas with his wife, arriving with other German immigrants on the ship Herschel. Settling in New Braunfels, Groos took part in the first public drawing for town lots, in April 1845. By 1850 he had bought 520 acres in the Waco Springs community, five miles north of New Braunfels on the Guadalupe River, but by 1857 he had returned to New Braunfels. From 1849 to 1860 Groos served as deputy surveyor and as surveyor of Comal County. In February 1862 Groos was elected captain of Precinct No. 2, Thirty-first Brigade, Texas State Troops. During his service with the militia he helped defend frontier settlements against Indian raids. Groos was county clerk of Comal County from 1862 to 1865, alderman of New Braunfels from June 1865 to September 1866, and mayor of New Braunfels from November 1872 to June 1873. As a surveyor, Groos located claims and boundary lines in Comal, Bexar, and Kendall counties. He also secured preemption rights and land patents for numerous clients. Groos pursued other activities as well: in 1866 he became an agent for the Aetna and Phoenix insurance companies, and in 1869 he purchased the Guadalupe Hotel in New Braunfels, which he managed until 1873. In August 1871 he was appointed to secure the right of way through Comal County for the International Railroad Company. Groos was elected commissioner of the General Land Office on December 2, 1873, and took office on January 20, 1874; he served in that office until his death on June 15, 1878. He was buried in the Austin City Cemetery.