Richard Thomas was well known in the social circles of southern Maryland and northern Virginia. A scion of a family of Maryland landed gentry, he was the son of Richard Thomas, Sr., former speaker of the House of Delegates, former president of the Maryland Senate, and brother of governor James Thomas of Maryland.
Born on October 27, 1833, Richard, Jr., was the eldest of three sons. All three fought for the Confederacy: Richard, Jr., in the episode of St. Nicholas, and both George and James William in Company A, Second Maryland Regiment, CSA (George as captain, James William as first sergeant). The latter two fought in Pickett's charge at Gettysburg. George was twice wounded: shot in the face at Cold Harbor and grievously injured at Gettysburg.
All three grew up under the sheltering maples of Mattapany, the family plantation on the south shore of the Patuxent River, five miles from its mouth and abreast of Solomons Island on the opposite side. The mansion, a long, stately building of brick, stood on level ground above a fifty foot bluff at the river's edge, with three hundred feet of grassy park extending from the veranda. (The mansion is now the official residence of the Commander, Naval Air Warfare Center, Aircraft Division, U.S. Naval Air Station, Patuxent.) Mattapany enjoyed a long history of entertaining the gentry of southern Maryland. In colonial days, the lord proprietor of Maryland often vacationed there in summertime, accompanied by a retinue of servants. Charles Calvert, third Lord Baltimore, came riding from St. Inigoes to court the beautiful daughter of the house, and the wedding that followed was remembered as a grand affair in the annals of St. Mary's County. In the Revolution, the ancestors of the Thomas brother stood in the Maryland line in the charge at the battle of Long Island.
Of the three Thomas brother, Richard, Jr., was the most spirited and daring. Even as a boy among the hard-riding, hard-drin