Jacob H. Plowman (September 5, 1836 – October 5, 1897) was an American politician from Maryland. He served as a member of the Maryland House of Delegates, representing Harford County from 1884 to 1888.

Jacob H. Plowman was born on September 5, 1836, in Laurel, Maryland.^[1][2]

Plowman learned the trade of a machinist. He worked for the Baltimore and Ohio Railroad.^[2] During the Civil War, Plowman served in the Union Army as a quartermaster's clerk.^[1] In 1872, Plowman moved to Harford County to pursue farming.^[1] He moved to New York City after the war and remained there until 1868. In 1868, he returned to Laurel to work in the machine and iron foundry business.^[2]

Plowman was a Democrat. In 1879, Plowman was elected as county commissioner of Harford County. He was remained in that office until 1883.^[1][2] He served as a member of the Maryland House of Delegates, representing Harford County from 1884 to 1888.^[3]

In 1887, Plowman was appointed by Governor Elihu Emory Jackson as commander of the Maryland Oyster Navy. He served in that role until 1891.^[1][2]

Plowman married Miss Smith from Oella, Maryland. They had one daughter, Ida C.^[1][2] He was a member of the Presbyterian Church, as well as the Masons and Odd Fellows.^[1]

Plowman died on October 5, 1897, at his home near Emmorton, Maryland. He was buried at Mount Carmel Church in Emmorton.^[1]