During the first 20 years of containerization, many container sizes and corner fittings were used; there were dozens of incompatible container systems in the United States alone. Among the biggest operators, the Matson Navigation Company had a fleet of 24-foot (7.32 m) containers, while Sea-Land Service, Inc used 35-foot (10.67 m) containers. The standard sizes and fitting and reinforcement norms that now exist evolved out of a series of compromises among international shipping companies, European railroads, US railroads, and US trucking companies.