Thomas Wiswall (1723-1791) was one of the several early settlers of Kennebunkport (then named Arundel) who were enslavers. He became wealthy as a shipowner engaged in the West Indies trade.

"A few of the inhabitants of Arundel were able to hold slaves. Mr. Prentice bought the first one owned in town, in 1734. Mr. Hovey also owned one, and probably sold him in 1747. Robert Cleaves, Thomas Wiswall, Samuel Hutchins, John Fairfield, Gideon Walker, Andrew Brown, and Jonathan Stone each owned a slave. Several of them were living in the town, but a few years since, the last two of whom died in the poor house, or which the son of the former master of one of them was an inmate." - Bradbury, p. 158

In 1751, Rev. John Hovey made an entry in his diary that "may indicate that the first vessel built on the Arundel side of the river might have been the schooner built for Thomas Wiswall. Although Wiswall of Newton, Massachusetts first lived at Cape Porpoise, ca. 1750, he built the first wharf in the confines of Arundel's Kennebunk River village and moved his family there from Cape Porpoise in 1754." - Butler, p. 30

"Thomas Wiswall, who had already made his fortune in shipping, built himself a fine new house and a store in 1787" on Union Street. - Butler, p. 35

"When this road [Maine Street] was located, there were but four houses where the village now is. The first one within its limits was built by Paul Shackford, about 1740 ... The second one which was a block house, was built by Rowlandson Bond, about 1743, and was occupied by Thomas Wiswall ... Gideon Walker built the third one in 1745...The house occupied by Daniel S. Perkins, which was built by his grandfather, Eliaphalet Perkins, was the fourth." - Bradbury. p. 151 (Note that Butler writes that Walker first built a smaller house circa 1740, making it the second.)

"From the close of the Revolutionary War to 1790, the wealth of Arundel increased rapidly. The business of the town was principally confined to ship building and lumber business, which were carried on extensively on the Kennebunk River. This caused the settlements on that river to multiply, and the village, which at the conclusion of the Revolutionary War contained only four houses* and one short wharf, had become the most populous part of the town. Many persons had engaged in the West India trade which was found to be very profitable....*The houses were those of Ephraim Perkins, Thomas Wiswall, Gideon Walker and John Walker." - Bradbury, p.178

Thomas Wiswall "built the first wharf on the eastern side of the Kennebunk river; and was engaged in the fishing, coasting, lumber, and West India business, and became wealthy. He owned the first West Indiaman in this District." - Bradbury, p. 286

Bibliography:

History of Kennebunk Port from its First Discovery (1602-1837) - Charles Bradbury

Kennebunkport - The Evolution of an American Town (Volume I - 1603-1923) - Joyce Butler

Family Search tree: https://www.familysearch.org/tree/person/details/K2V4-DQR