The powerhouse legal department of the modern United States, which decides so much of foreign and domestic policy as well as prosecutes criminals, came from humble beginnings. Over the course of its first century the United States did not need a full legal department. The Judiciary Act of 1789 created the attorney general, a part time position whose function was to provide legal counsel to the President. After the Civil War, the duties of the Attorney general greatly increased, and a string of legal cases necessitating the services of expensive lawyers prompted Congress to consider the creation of a whole department devoted to legal matters.

On this day, June 22, in 1870, Congress passed the Act to Establish the Department of Justice, “an executive department of the government of the United States” headed up by Attorney General.

The DOJ was tasked with conducting all lawsuits involving the country, as well as those in which the U.S. had an interest. In addition, the Department was put in charge of domestic law enforcement. The great increase in the scope and complexity of its duties spurred the creation of the office Solicitor General, who would help the DOJ in conducting its duties.