Officially known as St. Mary's of Aransas, it was the county seat of Refugio County for a short time. The town flourished from 1850 to 1886 and had up 5,000 residents. Regular lines of wagon and cart trains carrying cotton, hides, tallow and lumber operated between the port and Refugio, Goliad, Beeville, San Antonio, Uvalde, Gonzales and other points. The town was home to the first newspaper the "Vaquero" and the first college in South Texas. The town had two hotels, a brick yard, stockyard and several merchants. In its day it rivaled Galveston as the largest and busiest port in Texas.
When the Civil War began, most of the town's able-bodied men marched off to fight leaving the town defenseless. Later two federal warships captured St. Mary's unopposed. Yankee sailors burned two large warehouses and a wharf and sailed away.
In the 1880's the San Antonio and Aransas Pass Railway had planned to build a line into St. Mary's, but instead went into Rockport. In 1886 the wharves and the schoolhouse were destroyed by a storm; the next year, another storm proved even more destructive nearly destroying the entire town. Thereafter, the town dwindled steadily and finally faded out with the closing of the post office and general store in 1907. In 1908 two developers - E. O. Burton and A. H. Danforth acquired the land of the defunct town of Black Point renaming the area Bayside. In 1909, the post office reopened and the developers acquired adjoining land that was the former town of St. Mary's of Aransas. The town struggled to exist and was eventually incorporated as Bayside 1977.