Henry Onderdonk (d. 1895) was president from 1861 to 1864.
He was an educator in Baltimore prior to his election as Maryland Agricultural College president. Under his three-year tenure, eight students received degrees.
Onderdonk resigned under accusations, never substantiated, that he willingly harbored and entertained
Confederate troops under the command of General Bradley T. Johnson, who
had encamped on the College grounds.
He opened a private academy in Baltimore after resigning and concluded his education career as headmaster of St. James School in Hagerstown, Maryland, a position he held at the time of his death in 1895.