Soon after Riley and Ella Mays moved with their 12 children to Robstown in 1917, they and the Ira Collier family worked to organize this congregation. The first worship service was held in September 1918 in a Robstown school building, and the name given to the church was Mt. Zion Missionary Baptist Church. The Mt. Zion Missionary Baptist Association, a regional denominational organization, provided pastors for the new congregation during its formative years.
The Rev. C. B. Baycoat was the first minister called by the congregation, and he preached two Sundays a month. As new families joined Mt. Zion, a Sunday school was organized, and the congregation constructed its first sanctuary in 1930. By 1950, membership had grown sufficiently to require the ministry of a full-time pastor, and the Rev. D. L. Everett was called to that position. During his tenure, a new building was completed. In the latter half of the 20th century, leadership on the part of both ordained and lay members continued to inspire growth and development. A third building was constructed in 1965, and the Phyllis Wheatley School was purchased and renovated to create an activity center for the congregation. Throughout its history, Mt. Zion Missionary Baptist Church has focused on its commitment to outreach, education and community assistance. It remains a significant part of Robstown's cultural heritage.