Following the death of Major Denny, Robert Burns "fell heir to a big gray horse owned by Major Denny" as well as a mule known as Jim Longstreet, the mascot of Hood's Texas Brigade. Major Bums brought the mule and gray horse back to Houston at the close of the war. The mule was a familiar figure in Houston and died in 1869.

Major Bums accepted employment with Darling, Merriman & Company, the largest business house in Houston just following the Civil War. In 1866 he married Miss Lucy Munson and soon afterwards entered into the wholesale cotton and hide business under the firm name of Mitchell, Burns and Mitchell. After three years he disposed of his interest and entered the auction business with T. U. Lubbock in the firm of F. R. Lubbock & Son. Some fourteen years later, in 1884, he was appointed Postmaster of Houston by President Cleveland and held that position four years. He retired from active business following his service as Postmaster.

He was president of the oldest fire company in the city in 1870, Protection No. 1, formed August 14, 1838.  After replacing the old hand pump engine with a steam pump engine at the beginning of 1870, the company was called Protective Steam Fire Engine Company No. 1.

Robert Burns was a city alderman about 1874 and following and for 13 consecutive years was chairman of the Harris County Democratic Committee.  He participated in the organization of Hood's Texas Brigade Association of Confederate Veterans on May 24, 1872, and served as secretary. He took great interest in this organization and attended every annual meeting except the one just preceding his death.
Robert Bums received his first three Masonic Degrees in Holland Lodge No. 1; 1° on May 1, 2° June 22 and 3° July 31 all in 1858. He was Junior Deacon of Holland Lodge in 1859 and Senior Deacon in 1860.

He was a charter member of Gray Lodge and served as Junior Warden in 1871 and was then elected as Worshipful Master and served as the second Master of Gray Lodge during 1872.  He was a member of a large number of Grand Lodge Committees such as Returns of Chartered Lodges No. 1 and 3, Returns of U. D. Lodges, By-Laws, Credentials, Grievance and Appeals No. 2, Finance, Foreign Correspondence, Lodges of Sorrow and as chairman of the Committee on Masonic History in 1887 and 1888.

He was District Deputy Grand Master in 1879-1880 and 1880-1881, Grand Marshal in 1886-1887, 1888-1889 and 1889-1890.

He was a York Rite Mason and served as High Priest of Washington Chapter No. 2, R. A. M., in 1874-1875. He received the Order of High Priesthood on June 6, 1874 and was Grand Royal Arch Captain in 1877-1878.  He was created a Knight Templar in Ruthven Commandery No. 2, K. T., on June 20, 1884.

Robert Burns was a devoted and beloved Mason and his life was an example of worthy conduct and concern for his fellow man. He was for many years the chairman of the Masonic Relief Board in Houston and did yeoman service in this position.

He died at his residence at the corner of Main and Polk after a long illness on June 29, 1895, just five days after Gray Lodge passed its 25th birthday.  Religious services were conducted by Rev. H. D. Ames of Christ Church with the burial in Glenwood with Past Grand Master A. S. Richardson conducting the Masonic rites.'

Robert Burns was survived by his wife and five children: Robert, Jr., Edward, Miss Claudia, Malcolm and Miss Eleanor. All were present at his bedside except his youngest son, Malcohn, who was out of the state.