The great seal of Wisconsin, created in 1851, features the state coat of arms. The banner above the shield has Wisconsin's state motto: "Forward." Directly below this is a badger (the state animal). Supporting the shield are a sailor and a miner (the two most important industries of the state at the time it was founded).

On the shield itself are displayed:

- A plough to represent the farmers and agriculture of Wisconsin.
 
- A pick and shovel as a symbol of the early lead mining industry -
   galena ore (lead sulfide) is the state mineral of Wisconsin.
   The mining of lead ore was the principal occupation of the settlers
   of early Wisconsin, concentrated in the southwest corner of the
   state (in what are now the counties of Iowa, LaFayette and Grant -
   in the 1820's and 1830's, the population of these 3 counties was
   greater than that of Milwaukee or the east coast of Wisconsin).
 
- An arm and hammer to represent Wisconsin's artisans and
   laborers.
 
- An anchor as a symbol for the sailing and shipping industry.
   The western edge of Wisconsin is the Mississippi river (the
   chief shipping lane of mid-America during the early 1800's)
   and the upper part of Wisconsin is bounded by Lake Superior
   (source of the shipping trade for eastern Wisconsin).

The center of the shield is the United States shield with the motto E Pluribus Unum. Below the shield are a cornucopia (a symbol for the plenty of the state), bars of lead to represent Wisconsin's mineral wealth, and 13 stars which symbolize the thirteen original states. The coat of arms also appears on both sides of the Wisconsin state flag.

Source:

Seal of Wisconsin: Wikipedia.org

Links:

State Seals - 50 States List
National Seal