"The year 1909 marks a significant time in Mercedes history.  While the city of Mercedes was the fastest growing city in the Rio Grande Valley at that time, there is an even greater significance to Catholics living in and around Mercedes.  This year serves as a time when Mercedes received its first resident priest, and while missions already existed in Santa Maria and Toluca, Our Lady of Mercy became the foundation of missions in "The Cavalry of Christ" that ranged from Brownsville to Roma.  The Church was blessed on February 21, 1909 and dedicated to Our Lady of Mercy by a delegation led by Very Rev. H.a. Constantineau, D.D., Provincial of the Oblate Fathers of the South.

The first resident priests assigned permanently to Mercedes were Father Adrian Bornes, O.M.I., and Father Paul Hally, O.M.I. who together served not only Mercedes, but the surrounding missions as well.  Since the first resident priests, Father Bornes and Father Hally, Our Lady of Mercy has hosted a distinguished group of spiritual leaders.

For a more detailed history of Our Lady of Mercy during its first 50 years (1909-1959), we suggest you read the following accounting of Our Lady of Mercy, its history, and its role in the Catholic Churches of the of Valley and Diocese."

A Parish Remembers:  Fifty Years of Oblate Endeavour
in the Valley of the Rio Grande (1909-1959)

By:  Rev. Edward Kennedy, O.M.I. - Pastor of Our Lady of Mercy

IMPRIMI POTEST - Very Rev. John Hakey, O.M.I., Vice-Provincial
NIHIL OBSTAT - Most Rev. Adolph Marx, D.D., Auxiliary Bishop of Corpus Christi
IMPRIMATUR - Most Rev. M.S. Garriga, D.D., Bishop of Corpus Christi
Published: November 2, 1959