Eras of Party Government and Divided Government

The United States has three elective sections of national government, the president, the Senate and the House.  When one political party wins control of the presidency and both Houses of Congress, it is called partygovernment.  When at one particular time one party controls the presidency and the other party controls at least one House of Congress, this is called divided government.  Party government has been the norm through most of American history, although there have also been periods of divided government.  But since 1955, divided government has become the normal state of the American political system.  The table below shows the rising frequency of divided government.

The next table breaks down the period from 1801-1954 into sub-eras.