He had a family of three daughters, Catherine, Robina, and Mary Anne; and two sons, Andrew and John.
John, the younger of Robert MacMurray's sons, was born at Edinburgh in 1745.

After receiving a good general education, he entered the Royal Marines under the special patronage of Sir George Yonge, Bart., [Footnote: Sir George Yonge was Governor of the Cape of Good Hope, and subsequently Secretary at War; he died in 1812.] a well-known official of the last century, and his commission as second lieutenant was dated June 24, 1762.

Peace was signed at the treaty of Paris in 1763, and young MacMurray found himself quartered at Chatham, where the monotony of the life to a young man of an active and energetic temperament became almost intolerable.

He determined therefore to retire on half-pay at the age of twenty-three, and become a London bookseller! It is not improbable that he was induced to embark on his proposed enterprise by his recent marriage with Nancy Wemyss, daughter of Captain Wemyss, then residing at Brompton, near Chatham.
While residing at Chatham, MacMurray renewed his acquaintance with William Falconer, the poet, and author of "The Shipwreck," who, like himself, was a native of Edinburgh.
To this friend, who was then on the eve of sailing to India, he wrote: BROMPTON, KENT, _October_ 16, 1768.
DEAR WILL, Since I saw you, I have had the intention of embarking in a scheme that I think will prove successful, and in the progress of which I had an eye towards your participating.

Mr.Sandby, Bookseller, opposite St.
Dunstan's Church, Fleet Street, has entered into company with Snow and Denne, Bankers.