His son, Charles E. Welch, also a dentist, returned to Vineland, New Jersey, in 1875 and later relocated his dental practice to Vineland. By this time his father was a successful Prohibition crusader, and had "all but abandoned" attention to his old experiments. He advised Charles, "Now don't think I'm trying to discourage your pushing the grape juice. It is right for you to do so, so far as you can, without interfering with your profession and your health." Charles and Thomas Welch founded the Welch's Dental Supply Company in Philadelphia and began a dentistry journal. Charles promoted the sale and consumption of grape juice. The Welches sold grape juice as a sideline. The industry had grown slowly until 1890. So from 1890, the Welches were able to spend more attention on the industry. Charles did not devote full attention to marketing grape juice until 1893, when Welch's Grape Juice Company was "officially launched". However, Thomas Welch himself "never received a penny in return for his investment."
