After the 1943 closing of Stites Hospital, the Mercer County Board voted to construct a new hospital, which opened February 1, 1950. Generous financial donations were given to the hospital that began a tradition of Mercer County residents supporting their facility.
- Mrs. Harriet Batson Hayden of Pasadena, California established a trust giving 415 acres of prime farmland to the hospital.
- George Huffman willed $50,000 as a hospital trust fund.
- Elisha L. Essley, owner of the Essley Tool Company of Chicago, who in 1950 contributed $15,000 to the hospital, funded the surgical suite.
- Olive Lant, Beatrice Leona Bopp, Ludwig Samuelson, and Clarence L. Anderson also donated substantial funds to financially strengthen the hospital.
By the late 1950's, the hospital was operating at maximum capacity. Many times there more patients than available beds. In 1972 new state licensing requirements had to be met in order to meet the Life Safety Codes and participate in the Medicare Program. The hospital would need to make several improvements in order to meet the new requirements.
Mercer County Board realized the need for a new facility and voted in 1980 to build a new hospital. Construction began July 1, 1980; a Grand Opening and Dedication Ceremony were held on February 26, 1982.
In 2008, with significant changes in the healthcare indusctry, a renovation of the 28 year old building seemed imminent. The most significant areas of improvement would be the HVAC system, expansion of the Laboratory, Physical Therapy, Radiology and Emergency Departments. The Surgery Department would also be expanded and all patient rooms converted into singles for privacy and safety. It was at this time that the Mercer Foundation for Health rallied the community for support and conducted a successful $1 million dollar capital campaign to help with the cost of the renovations.
Genesis Health System acquired Mercer County Hospital and Mercer County Nursing Home and Medical Associates Clinic on February 1, 2013. The three were re-named Genesis Medical Center, Aledo; Genesis Senior Living, Aledo; and Genesis Health Group, Aledo. The two entities (hospital and nursing home) are linked by a walkway and plans were made to combine services for cost savings. The largest cost saving could be achieved by combining the food services departments. The senior living kitchen and dining room were renovated to accommodate the change.
After extensive planning, the ground-breaking for the hospital renovations was held in June of 2013. The renovation project was completed on time in June, 2015 and on budget at $12 million.