What is the beef trust mentioned in The Jungle?

A trust is
any group or organization that controls supplies or commodities of some sort. There are various
trusts that work with conglomerates and organizations to control and maintain the production of
various goods like pharmaceuticals, agricultural products, and similar items. In the book, the
beef trust is a group of organizations with a vested interest in the production and sale of
beef.

There are several major players that all run various packing houses in
Packingtown, and they make up the regional industry of meet production. Because of their
ownership of and interest in the industry, they have become the Beef Trust. Together, they
control all the production of meet in the region of Packingtown and work to ensure that the
market remains stable and in their favor.