He found work as a clerk at the age of 14 with merchants James Hamilton and John Warren at Queenston and later at Sterling (now St. Thomas).
In 1832, he moved to London and opened a general store and also sold dry goods wholesale, in partnership with George Jervis Goodhue.
He was named an officer to settle rebellion losses claims in the district in the same year.
He was also president of the London and Port Stanley Railway and a director of the Bank of Upper Canada.
Following a downturn in the economy and the death of his son-in-law, Lawrason was forced to declare bankruptcy in 1864.