When his regiment departed Fredericton in 1823, he stayed behind, joining the merchant firm of Thomas L. Langen as a clerk. Thomas soon became a full partner, and their business operated under the name of Langen & Robertson. This continued until 1831, when Mr. Langen retired and the business was then taken over by Thomas.
T. R. Robertson’s store was located on the west end of Queen Street, and continued to operated in the same location. On August 2, 1839 his store was destroyed by a fire – described by the Fredericton Sentinel as the most disastrous of the decade. Nevertheless, T. R. Robertson’s store was rebuilt and continued for another 17 years.
Thomas was a highly respected money-manager. In 1855, he was appointed by the Province as Deputy Treasurer of Fredericton, remaining in that position until Confederation in 1867; he was then appointed Canada’s First Collector of Customs for the Port of Fredericton. He was also one of the tax assessors for the City of Fredericton, and a Director of the Central Bank of New Brunswick.
Thomas participated actively in the religious life of Fredericton, and is credited – along with his close friends and fellow Society members Francis Beverly, Robert Fulton, John Gregory, and Robert Gowan – with founding St Paul's Church. He was also one of the church’s original trustees and was their first Treasurer.
Thomas R. Robertson and his wife Fanny are buried in section 8 of the Old Burying Ground. Thir gravestone reads:
Sacred
to the memory of
Fanny,
to the memory of
Fanny,
wife of
Thomas R. Robertson,
Thomas R. Robertson,
who closed her mortal life in prospect
of a blessed immortality on the
29th day of May, A.D. 1838
in the 38th year of her age.
Also of
Catherine,
their infant daughter, who
Died on the 20th day of August
Catherine,
their infant daughter, who
Died on the 20th day of August
aged 4 months and 4 days.
Also
William Reid,
Born 1831
William Reid,
Born 1831
Died at New York, 1866
Frances,
Born 1835
Died 1869
Born 1835
Died 1869
Isobel
Born July 1833
Died Jan 1877
Died Jan 1877
Thomas R. Robertson,
Born July 25, 1795, Died October 16, 1878
Born July 25, 1795, Died October 16, 1878
also his daughter
Mary Ann
Mary Ann
Born August 24, 1836, Died May 16, 1898.