Sweetser was born in Newburyport, Massachusetts. He toured Europe and climbed in the Alps on a two-year jaunt before returning stateside and writing travel guidebooks along the lines of the Karl Baedecker's series he relied on in Europe.[1]
The Mount Washington Observatory Collection has an image of Sweetser. He helped encourage visitors to the White Mountains of New Hampshire with his guidebook.[1]
The Maritime Provinces: a handbook for travelers, a guide to chief cities, coasts and islands of the Maritime Provinces of Canada, and to their scenery and historic attractions, with the gulf and river of St. Lawrence to Quebec and Montreal, also Newfoundland and the Labrador coast, Boston : J.R. Osgood, (1875)
White Mountains, a handbook for travelers (1876)
Allston, Boston, Houghton, Osgood and Company (1879)