Founded in 1899 and still in business. This from Wickepedia:
Historically, ACF built passenger and freight cars. One of the largest customers was Union Pacific, whose armor-yellow carbon steel lightweight passenger rolling stock was mostly built by ACF. Famous dome-observation Native Son was an ACF product. Today, the American passenger car market is erratic in production, and is mostly handled by specialty manufacturers. Competitors Budd, Pullman-Standard, and St. Louis Car have all either exited the market or gone out of business. Currently, ACF builds mostly covered hopper cars for hauling items like corn or other grains. Other products are mainly miscellaneous steel products.