During the 50's, business grew and many new employees were hired. John S. Mueller joined the company as field salesman and grew with the company, under the tutelage of his father, Victor. Upon Victor's death in 1963, John S. became president and Chief Executive officer of the company. John B. Mueller was vice president of manufacturing and manager of the Peoria plant during this time.

In the years that followed, Laidlaw purchased and sold many small companies. Among them were a distributor of building materials, a manufacturer of brass plated wire furniture, and a manufacturer of wooden garment hangers.