The Constitution of the United States of America does not mention local governments.  Local governments are created by and regulated by the states.  This means that to speak about cities or other forms of local government in the United States is to speak about fifty different legal and political situations.  The states outline the powers of municipal governments in charters.

Historically, there are four forms for municipal government in the United States: 

• the mayor-council;
• council-manager;
• commission; and
• town meeting. 

A recent survey determined that the predominant forms are:

• Council-Manager form of government with 58%
• Mayor-Council form of government with 38%
• Other form of government with 4%  (Including the commission and town meeting)

Recent studies indicate that the distinctions between the mayor-council and the council-manager forms are becoming smaller and smaller.  City officials continually change the structure of the municipal government.  Those cities with a primarily mayor-council form often adopt features to improve management, while council-manager cities adopt features to increase their political responsiveness, and leadership.

Sources:
DeSantis,Victor S. and Tari Renner. "City Government Structures: an Attempt at Classification"   State and Local Government Review, vol. 34, no. 2, (Spring 2002).

Barnes, William R.  Forms and Structure of Municipal Government in the United States, presentation to the Convention of Scottish Local Authorities on October 24, 1991, in Edinburgh, Scotland.

Frederickson, H. George,  Curtis Wood, and Brett Logan. "How American City Governments Have Changed: The Evolution of the Model City Charter" National Civic Review. vol. 90, no. 1, (2001).

Frederickson, H. George, and Gary Alan Johnson. "The Adapted American City: A Study in Institutional Dynamics."  Urban Affairs Review, vol. 36, no. 6 (July 2001).

National League of Cities. Choices of the Citizenry: Forms of Municipal Government. Washington, DC: National League of Cities, May 1989.

Svara, James H. "The Shifting Boundary Between Elected Officials and City Managers in Large Council-Manager Cities"  Public Administration Review, vol. 59, no. 1 (January-February 1999).

Svara, James H. Two Decades of Continuity and Change in American City Councils. commissioned by the National League of Cities, September, 2003.