Congressman from the sixth district of Maryland, serving two terms from 1875 until 1879.

Born in Killeenmore County Offaly , Walsh emigrated to the United States in 1842 and settled in Virginia.

He graduated from Mount St. Mary's College of Emmitsburg, Maryland, and began studying law.

He was admitted to the bar in Virginia in 1850, and commenced practice in Cumberland, Maryland in 1852.

Walsh served as a member of the Maryland Constitutional convention in 1867, and was later elected as a Democrat to the Forty-fourth and Forty-fifth Congresses (serving from March 4, 1875, until March 3, 1879).