The Quadriga is formally called "The Progress of the State" and was created by Daniel French and Edward Potter. It is covered with 23 1/2 karat gold leaf and was restored in 1994-5 having been originally installed in 1906. It's actually copper and steel underneath.
The statue consists of 2 women, 1 man and 4 horses. The horses represent nature's four elements, namely, earth, wind, fire and water. The man symbolizes prosperity while together the women stand for civilization, but separately industry and agriculture.
The word quadriga is actually latin for four (quadri) and yoke (iugum) and has a long history in classical mythology as well as Roman chariot racing and the ancient Olympiad games. The quadriga in Minnesota is not the only one in the world. There are more than 10 still standing around the globe with the oldest one dating back to 1793 in Berlin.
The Minnesota Historical Society offers regular tours to an exterior platform providing close-up access to the statue - from the rear. So while it's not the best view of the structure, it does give one nice views of the city of Saint Paul and the Cathedral.
Have a look at several images I made of this golden icon, some on the ground and some from the tour platform. And most importantly, to all those celebrating it, have a wonderful Thanksgiving and Happy Hanukkah!