in 1840, the 24-year-old bartow campaigned for william henry harrison, the whig candidate for president. in 1841, he began his own political career by serving the first of two consecutive terms in the georgia house of representatives, followed by one term in the georgia senate. in 1844, bartow married louisa greene berrien, the daughter of one of his previous professional tutors, sen. john berrien. in 1856, bartow was a candidate for the u.s. congress but was defeated. the following year, he was elected as captain of savannah's 21st oglethorpe light infantry, a reserve guard company that had been formed in 1856. he served as an instructor to the volunteers, many of which were young scions of established families in local society.