Roland P. Hazard, physician, and John C. Caswell, a wholesale and retail druggist, were located at 12 Washington Square and 132 Thames Street in Newport, Rhode Island in 1856.

Their sons, Roland R. Hazard and Phillip Caswell, both residents of New York City, took over the company from their fathers in 1857 becoming Hazard & Caswell. They dealt in medicines, perfumes, brushes, soaps, artists materials, and other items. They became proprietors of Formodenta tooth paste, a liquid dentrifice called Amber Wash, Dentine, a safe and elegant tooth powder, Feke's Vegetable Dyspepsia Bitters, and several inks and ink and grease removers.

By 1863, John R. Caswell of Newport and Henry F. Mack and Phillip Caswell, Jr. both from New York City, joined together and took over the company changing the name to Caswell Mack & Co. The company was located in both Newport and New York City.

In the early 1880's, the company's name changed to Caswell-Hazard & Co., Family & Dispensing Chemists and still remained in the Newport location as well as the Fifth Avenue Hotel on Broadway at the corner of 24th Street, and at Sixth Avenue at the corner of 39th Street both in New York City.

Later, from 1887 to 1893 the company became Hazard, Hazard & Co. and was run only by John C. Hazard and Roland N. Hazard.

In the late 1890's, John R. Caswell, William M. Massey, and Lyman B. Blackman joined together and were operating out of Newport on Thames Street and another location on Bellevue Avenue, and also in New York under the name Caswell Massey & Co. By 1906 they were succeeded by Hall, Lyons, & Co., New England Apothecaries, 212 Thames Street in Newport and continued until 1915.

The company was still in business, reverting back to the Caswell-Massey name sometime in the past, as evident in their ad in the Providence Evening Bulletin dated August 8, 1980. The ad stated that their motto was, "The Fragrant World of Caswell & Massey."