 The company has expanded organically and through acquiring startups that align with the company's mission.HSA Headquarters is located at 67 Mount Auburn Street, Cambridge MA, in the former Manter Hall School building which was built in 1927.Established in 1884, Manter Hall School helped students prepare for Harvard's entrance exams during the 1930s and offered four- and eight-hour review sessions before every major Harvard mid-term and final examination.