irregular past participle of buy, used as an adjective from 1793, especially in colloquial U.S. usage, of clothing and other items, opposed to "made."
BOUGHTEN. Which is bought. This is a common word in the interior of New England and New York. It is applied to articles purchased from the shops, to distinguish them from similar articles of home manufacture. [Bartlett, "Dictionary of Americanisms," 1848]