Complex sentence: Dofasco owned and operated a number of subsidiaries, including National Steel Car, a Hamilton-based railway freight car manufacturer, from 1962 to 1994, and Algoma Steel, from 1988 to 1991, until union and financial difficulties ultimately forced Dofasco to divest the company.
Split into simpler sentences: Dofasco owned and operated National Steel Car, a Hamilton-based railway freight car manufacturer, between 1962 and 1994. Additionally, it owned Algoma Steel from 1988 through 1991, until union and financial difficulties ultimately forced Dofasco to divest the company.