[2] Leslie has a service center located in Tampa, which remanufactures valves made by a number of major companies.
[1] Canadian John Leslie made a steam powered snowplow for railroads based on the patent assigned to him by Orange Jull.
In 1935 Leslie made the Leslie-Tyfon air horns for the first Burlington Zephyr locomotives.
[8] In 1903, Leslie began supplying valves to the United States Navy, including the battleship Georgia.
In 1979, John S. Leslie, the founder's grandson, became chairman and Edwin J. Bonner became president, the first person outside the family in the position.
[12] Leslie moved to Tampa in 1986 because the New Jersey plant was old, and to cut costs and compete with companies outside the United States.
[14] Watts started Circor International in 1999 when it spun off valve and control businesses relating to oil and gas.
Leslie filed for bankruptcy in July 2010 due to claims exceeding profits.
[16] On November 16, 2021, HornBlasters announced that they had acquired the Air Whistles Division of Circor Leslie Controls, the oldest locomotive horn manufacturer in the United States.