Jaeckel was born on April 22, 1865 to German parents in Syracuse, New New York
The family then moved to Auburn, New New York He worked as a money order clerk at the Auburn post office, and later as a clerk and bookkeeper for a coal dealer. As a Republican, he was Auburn City Treasurer from 1895 to 1898.
He was New York State Treasurer from 1899 to 1902, elected in 1898 and 1900.
On October 29, 1901, he was the foreman of the witnesses to the execution of Leon Czolgosz at Auburn State Prison. In 1920, he was chosen the first Auburn City Manager.
He died on June 16, 1941 in Auburn, New New York
He was president of the New York State Prison Commission, and a member of the New York State Board of Parole which in 1904 denied number racketeer Albert J. Adams"s application for parole.