The Library was established in 1948, as part of the Civic Center Complex on Kansas Avenue. It originally occupied the present City Manager's office, and was run by community volunteers. Mrs. Pearl C. Doss provided a seed grant for the library's collection of $8,000.00 in memory of her late husband, Porter Phelan Doss, an active local businessman and civic leader.

In 1966, the City of Weslaco provided funding for construction of its first facility, the building now houses the Weslaco Bicultural Museum. The first professional librarian , Frances Wyatt Isbell, was hired in 1971. In the early 1980's, the citizens of Weslaco approved a bond issue of well over one million dollars for the construction of the present facility, which opened its doors to the public in January 1986.

The library complex includes a two-story main building in the Spanish style with a media center. The two sections are joined by a shady courtyard featuring a fountain and tropical plantings. Designed by Weslaco architect, Gene P. Hobart. The interior stairway is decorated with terracotta and blue Mexican tile in the talavera pattern.

Patrons have access to books, large print materials, a Texas history collection, audio books, videocassettes, art prints, word processors, and the Internet. The library is host to many programs of local and Valley interest in its well-appointed theater and meeting complex, seating 174. Other services and features include the Literacy Center, a Homework Help Center, the Friends of the Library Bookstore, an annual summer reading program for children, monthly exhibits, and concerts.