The academy was founded in 1907; its mission is to educate young men and women within a nurturing community based upon Christian values.

After an organization drive that began in 1905, the Southwest Texas Baptist Conference established the school in 1907 by matching $25,000 raised by citizens of San Marcos.

Thomas Green Harris succeeded Carroll, and the Christian Education Program of the Baptist General Convention of Texas began administrative oversight in 1911.

Girls have also participated in military training on an optional basis since 1973 when two students, Mary Shepard and Karen Stubbs led the development of the first female platoon.

Also in January 1982, under the administration of Jack E. Byrom the academy moved from its location at the current Texas State University campus, to a more spacious lot on Ranch to Market Road 12.

Green and Purple of the Laurel, bind us though we part Keep the spirit ever with you, deep within your heart Men and women of tomorrow, we’ll be proud of you The lives you now are building will be strong and true There’ll be echoes in your memory of cadets out on parade And of students in the chapel with their heads bowed as they prayed Fellowship is given those who come from far and near To these hallow’d halls of learning which we hold so dear Blessed are the lessons learned, and through the years may we Be ever true to you, San Marcos Academy The mascot of SMA is the bear: the boys' sports teams are referred to as “Bears” and the girls' teams as “Lady Bears”.