"Board of Aldermen" is the governing body of many jurisdictions in the United States. In these jurisdictions, the term is used instead of city council and its members are called "Alderman" or "Alderwoman", while in the state of Wisconsin, the term "Alderperson" is officially used.
Some cities, such as Chicago, mix the two terms, thereby having a city council composed of aldermen. Some states such as Pennsylvania established aldermen in the 19th century to serve as local judges for minor infractions. Pennsylvania's aldermen were phased out in the early 20th century. In this manner depending on the jurisdiction an alderman could have been part of the legislative or judicial local government.
Boards of Aldermen are used in many rural areas of the United States as opposed to a larger city council or city commission. [Wikipedia]