Adam Clark Williams from Chagrin Falls, Ohio founded this company in 1886, but the production of toys actually started in 1893 after a fire made the firm move to Ravenna, Ohio.
Williams was largely known for the design & production of cast iron cars & trucks, but only a few tin vehicles were produced and are very rare today. The company ceased toy production in 1938.
The A.C. Williams Company, Inc. of Ravenna, Ohio still owns Lite Metals, Tri-Cast was sold in April of 2000. You can read a long history about AC Williams on their website.
What's it worth? Take a look at this Williams price guide: sold listings for a value indication.