In 1938 the U.S Department of Agriculture was established which led to the study of crops, soil, water conservation, fertilizer use, insects, plant diseases, and the effects of climate.

The Construction on the overhead tank of Weslaco’s water storage reservoir was completed in 1941, making it one of the city’s iconic landmarks.

In 1945 the Chamber of Commerce made a deposit of 1,012.50 on land for the airport, in 1945, it was named the Mid Valley Airport. The first Miss Weslaco pageant was held, naming Linda Link Hunt as the first Miss Weslaco.

Knapp Medical Center opened in Weslaco on January 2, 1962, as Knapp Memorial Methodist Hospital.

A 50^th Anniversary celebration was held on December 4th-7th 1969!

On April 2^nd 1970 the first performance of the Mid-Valley Civic Theatre was held at The Tower Theatre. During the 1960s a collection of stories and artifacts from prominent businesses and families served as the basis for a book published on the City’s 50^th anniversary. in 1971 The Weslaco Museum was formed to give the collection a permanent home!

In 1983 Dr. Leonard Pike developed the 1015 Sweet Onion at the Texas A&M AgriLife Extension Center!!

In 1984 the Valley Nature Center is established as a non-profit organization, making it the oldest nature center in the Rio Grande Valley.

The first Texas Onion Festival is held at Harlon Block Park in 1989. (Now Isaac Rodriguez Park)

In 1992 Bebe Skaggs James, daughter of early Weslaco residents C.L. “Lester” and Florence Skaggs, donates property to Frontera Audubon Society for conservation and preservation. This led to the opening of this current location in 2000.

In 1997 the 1015 Sweet Onion was named the State Vegetable of Texas by the 75^th Legislature of the State of Texas.

In 2002 Weslaco received the All-America City Award, it was presented by the National Civic League. Weslaco was one of 10 municipalities to receive this award nationwide.

In 2006 the Texas Parks and Wildlife Department began piecing together land that would become Estero Llano Grande State Park. The grand opening for the State Park was held in June of 2006

In 2011 the Weslaco Economic Development Corporation held its first Alfresco Weslaco in Downtown Weslaco.

The city of Weslaco named “Paso Del Norte” to “Dolores Huerta Blvd” in 2012, making it the first street in Texas to be named after the United Farm Workers Co-Founder.

2019 marked Weslaco’s 100^th Anniversary, the celebrations included the annual parade held by the Weslaco Area Chamber of Commerce, A multi-day festival and the creation of a new time capsule with items donated by families from all over Weslaco!