Their main headquarters building, Mather Tower, built in 1928 in Chicago, still stands today.
As the 20th century dawned, Mather began leasing stock cars to the railroads that used them.
Railroads of the time found it less expensive to lease stock cars than to purchase them outright or to build them.
With the onset of the Great Depression in the US, Mather was one of a limited number of companies that saw profits in the 1930s.
In the late 1950s Mather was merged into the North American Car Corporation of Chicago.