http://en.wikipedia.org/wiki/George_R._Dennis

George Robertson Dennis (April 8, 1822 – August 13, 1882), a Democrat, was a United States Senator from Maryland, serving from 1873-1879. He also served in the Maryland State Senate and the Maryland House of Delegates.

Dennis was born in Whitehaven, Maryland, and graduated from Rensselaer Polytechnic Institute in Troy, New York. He entered the University of Virginia at Charlottesville, and studied medicine at the University of Pennsylvania at Philadelphia. He graduated in 1843 and practiced in Kingston, Maryland for many years, until later devoting himself to agricultural pursuits.

In 1854 and 1871, Dennis served as a member of the Maryland State Senate, and in 1867 served in the Maryland House of Delegates. He was elected as a Democrat to the United States Senate and served from March 4, 1873, until March 3, 1879. He died in Kingston in 1882, and is interred in St. Andrew’s Churchyard of Princess Anne, Maryland.