TERRE HAUTE - The largest employer in Terre Haute is marking a milestone. Union Hospital will Thursday celebrate 125 years since its founding as the Terre Haute Sanitarium. It began as a small operation with only three paid employees and has since grown to include more than 2,000 employees with facilities in both Terre Haute and Clinton.

Construction of its 380-bed, $185 million main campus was complete in early 2010 and hospital officials say it's the largest single building project in the Vigo County city's history. It was founded in 1892 by Dr. Leo Weinstein and Dr. Benjamin Swafford. In 1900 it became home to the city's first school of nursing. A 2014 annual report shows nearly 13,500 patients were admitted and $227.1 million in operational expenses.