A more thorough explanation:

A loan society is a type of club that is organized to collect deposits from industrial workers and provide them with loans. These societies were popular in England and were the forerunners of the American savings-and-loan associations.

For example, a group of factory workers might form a loan society to help each other save money and borrow funds when needed. Members would make regular deposits into the society's fund, and then could apply for loans at a lower interest rate than they might get from a bank.

This type of organization was especially important in the days before widespread access to banking services, and helped working-class people to build up savings and access credit when they needed it.