When a young Irish woman named Catherine McAuley received an unexpected inheritance, she gave thanks to God and her benefactor. Catherine used those funds to open the first House of Mercy, serving impoverished women and children in Dublin. In early 1875, the Sisters of Mercy came to the South Texas town of Indianola. Only a few months later, a severe tropical storm destroyed the town, and the Sisters were forced to relocate to Refugio, Texas.

In 1894, the motherhouse for Sisters of Mercy of South Texas was moved from Refugio to Laredo, under the leadership of Mother Mary Clare O’Connell. Along with another Sister and a postulant, Mother Mary Clare established Laredo’s first hospital, a 12-bed facility, which launched the Sisters of Mercy to engage in acute care/hospital ministry for close to 110 years in Laredo, TX. The Sisters taught at many public and parochial schools in South Texas. They also established two nursing schools, a school of radiology technology and laboratory technology. 

Today, Mercy Ministries of Laredo is a continuation of the works of mercy begun by the Sisters of Mercy in the late 1800s. This community outreach ministry includes two distinct entities: Mercy Clinic, a primary care clinic, and Casa de Misericordia, a domestic violence shelter and education center.