He became a salesman of steel pens, then opened a jeweller's shop, and finally entered the business with which his name was most identified, that of money-lending.
Nearly every noble family in Great Britain is said to have been more or less in business connection with Lewis.
Upon his death, he left an endowment of £670,000 to set up a charitable trust to provide housing for the poor.
Samuel Lewis Housing Trust completed its first properties in 1910 at Liverpool Road in Islington, London.
This was followed by other large London schemes at: all of which carry the name Samuel Lewis Housing Trust Estate.