Founded in 1983, Seaport Steel is one of Seattle's largest independently owned structural steel and plate distributors. Its roots are established from Isaacson Steel in 1907. Isaacson was primarily a structural steel distributor. It conducted business in Seattle until it closed operations in 1983. At that time, Seaport Steel was formed by purchasing the inventory and equipment of Isaacson's Steel Service Division. In 1984, Seaport Steel bought the Steel Service Center. This plant specialized in steel plate and plate processing. By combining the two, Seaport is able to offer not only structural steel items but also cut and processed steel plate. Seaport Steel is a major supplier to construction, manufacturing and shipbuilding companies in the Northwest.