Quadriga

A notable feature of the State Capitol in Saint Paul, Minnesota is a gilded statue of a chariot pulled by four horses. 

The four horses represent the classical elements of water, fire, air, and earth. The female figures standing among the horses represent agriculture and industry. 

The male charioteer represents prosperity. Added together, they represent civilization. The 1906 group called "Progress of the State" was sculpted by Daniel Chester French and Edward Clark Potter. 

This arrangement of sculptural elements goes back to ancient Rome and is known as a quadriga. They usually appear on triumphal arches. In ancient mythology, the chariots of the gods were in the quadriga configuration, with four horses abreast. The sculpted horses on St. Mark's in Venice were from a Byzantine group. 

Quadrigas were raced in the ancient Olympic Games, as demonstrated in the 1959 movie 'Ben Hur.' 

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Wikipedia on Progress of the State and Quadriga