The 1895 to 1915 period was a time of the rapid growth in manufacturing, rail transportation and wholesale operations.
During this period the Waterloo Gasoline Traction Engine Company moved to Waterloo and shortly after, the Rath Packing Company moved from Dubuque.
On June 7, 1934, bank robber Tommy Carroll had a shoot-out with the FBI when he and his wife stopped to pick up gas.
The black community felt the death was suspicious, and protests were held.
On June 4, Weems led a march on city hall to encourage investigation into his death.
In 1910, a significant number of black railroad workers were brought in as strikebreakers to the Waterloo area.
In 1948, a black strikebreaker accidentally killed a white union member as he tried to escape the striker's ire.
Another major employer throughout the first two-thirds of the 20th century was the Illinois Central Railroad.