A tavern or bar where the owner is required to purchase some or all of its products from a single manufacturer.
Tied houses are illegal in the United States, although the relationships between some bar owners and distributors owned by large manufacturers look at times to be tied houses. Tied houses are more of an English phenomenon as tied houses were declared illegal in the United States after Prohibition.
You can find the declaration of the illegality of tied houses at 27 U.S.C. § 205