Background
He was born in Dresden, Germany.
He was born in Dresden, Germany.
Gerber immigrated to the United States in the 1830s and enlisted in the 4th United States Infantry in 1839, retiring a first time in 1844. He joined the 1st Engineer Battalion when it was created in 1846 and served in the Mexican-American War. During the Battle of Mexico City, he is said to have saved the life of then second lieutenant George B. McClellan.
During the American Civil War, Gerber was responsible for training volunteer recruits into combat engineers.
In September 1864, he was promoted to Sergeant Major, becoming the senior enlisted soldier in the Corps of Engineers and the first person to hold this rank. He was appointed adjutant of the Corps of Engineers in February 1867.
He was offered a commission on several occasions, but declined each time. He was the first United States Army engineer to receive the medal.
He was buried in Cypress Hills National Cemetery in Brooklyn.