Francis Mewburn was born in Newcastle-upon-Tyne in 1785 and went on to set up his legal practice in Darlington in 1809. In 1831 he bought a house near Coniscliffe Road and re-named it Larchfield.

As a prominent Darlington lawyer, Mewburn was appointed alongside Leonard Raisbeck of Stockton as joint solicitor of the Stockton & Darlington Railway Company (S&DR). He spent time in London during 1819 and 1821 lobbying for support to pass the various legislation for the railway. The relationship between the two men was strained, Mewburn felt he was the superior legal professional and that his contribution to the railway's success was solely a result of his work. Historical opinion regarding the respective contributions of the two lawyers to the opening of the S&DR appears to be polarised. Upon Raisbeck’s resignation in 1828, Mewburn became the S&DR’s sole solicitor. When Mewburn retired some years later in 1860 he had rendered a total of 42 years of legal assistance to the company.

Mewburn authored at least one pamphlet, in 1830 he published ‘Observations on the Second Report of the Commissioner’s appointed to Enquire into the Law of Real Property’ which opposed the proposal that title deeds be stored in a central repository in London. Mewburn served as the Chief Bailiff of Darlington from 1842 to 1860. Like many of the S&DR promotors, Mewburn was a Quaker. On his death in 1867 he was afforded a public funeral by the town of Darlington.