The legal system of the United States is a "dual track system", that is, federal law and state law coexist, and the United States is a case law country, so there is no unified lawyer law in the United States. Laws and regulations concerning the lawyer system are scattered in the Constitution, case law and the Lawyers Law formulated by the Lawyers Association. Some people divide American lawyers into three types according to their positions: lawyers employed by government agencies, lawyers employed by enterprises and companies, and lawyers who run law firms ("listed lawyers"). The first two kinds of lawyers are employees of the government or enterprises. They only handle the legal affairs of their own government agencies and companies, and do not accept the entrustment of the parties in society. The latter is a lawyer who performs his duties in society, serves the unspecified majority in society and obtains a business license, so he is also called a "listed lawyer". In recent decades, there have been some lawyers specializing in a certain law and handling certain cases in the United States, and the tendency of division of labor among lawyers has become more and more obvious. At present, a number of professional lawyers such as patent lawyers, contract lawyers and tax lawyers have appeared in the United States.
The American lawyer system originated in Britain, but it did not inherit the traditional practices such as grading system and business monopoly in the British lawyer system.