Elisha P. Wilbur, a trusted associate of his uncle, Asa Packer, served the university as treasurer or trustee from its opening until his death. The Wilburs migrated from Mystic, Connecticut to Mauch Chunk, Pennsylvania in 1838 to join Packer in his business enterprises. After finishing school, Wilbur worked in one of Packer's stores, and was on the Lehigh Valley Railroad survey crew. In 1856, Wilbur became his uncle's private secretary and was in charge of the finances of Packer's enterprises.
Moving to South Bethlehem, Wilbur became involved in business and civic affairs, organizing the banking house of E.P. Wilbur and Company in 1870, which was charted as the E.P. Wilbur Trust Company in 1887. After Packer's death, he served as president of the Lehigh Valley Railroad until it was sold in 1893. He also was involved in the management of the Bethlehem Iron Company. "He was a large factor in everything that entered into the making of the history of the Bethlehems during the past 50 years," The Bethlehem Globe noted in his 1910 obituary.
After Packer's death, Wilbur and Robert Sayre dominated the Board of Trustees. Wilbur was on the executive committee, the library committee, and chairman of the building committee. During the university's fiscal crisis in the 1890s, Wilbur and Sayre crafted the package that restored Lehigh's financial stability, loaning the university their own money. Wilbur endowed Lehigh's first prize, the Wilbur Scholarship, for the sophomore with the highest average. Later he added to the fund to establish freshman and sophomore prizes in mathematics, English, German, French and physics.