T.S. Martin and Company, also known as Karlton's, Fishgalls & Cameo, is a historic building located in Sioux City, Iowa, United States. It is an L-shaped structure that fronts both Fourth Street and Nebraska Street. It was occupied by one of three locally owned department stores from 1894 to 1919. The buildings on Fourth Street were originally built in 1885. T.S. Martin and Company itself dates from 1880 when Thomas Sanford Martin opened a dry goods store in rented commercial space. He first acquired 515-517 Fourth Street in 1885, which he leased to a clothing store, and his brother Louis opened T.S. Martin and Company Shoes by leasing 519 Fourth Street the same year.