When the Civil War broke out, he enlisted with the Union Army, serving a hundred days with a branch of the Wisconsin Volunteers.
In 1868 he received a Bachelor's degree, followed by a Master's three years later from Michigan State Agricultural College.
Ten years later, he became first Director of the Mississippi Experiment Station.
Tracy is well known for his work in the taxonomy of various grasses, plant breeds, and for adapting numerous forage plants to the biomes of the Southern United States.
[1] The following list can be found at the Biodiversity Heritage Library:[2] Tracy edited the exsiccata-like series Plants of the Gulf States, collected and distributed by S. M. Tracy and was co-editor of the exsiccata Plants of Southern Colorado.