Sounds like you have a replica of a California gold piece made by the mysterious Cincinnati Mining and Trading Company. These coins were privately minted during the famous gold rush that was getting started in 1849. Genuine pieces today soar into the 100s of 1000s of US dollars. But, since oodles of replicas have been made, and there are only 8 known genuine pieces, yours is most surely a reproduction and worth a few dollars.
You can see more about similar coins at this CoinQuest link.
Mike Locke is a recognized expert on coins like yours. You can visit his neat web site at calgoldcoin.com. Here is what Mike has to say about your Cincinnati coin:
'The Cincinnati Mining and Trading Co. never succeeded in making gold coins in California. They did make a couple of pattern pieces before they headed out west. These pieces are extremely rare and valuable today. Most of them are gold and weigh about 33grams. HOWEVER, a company called Martguild makes brass or gold plated cast zinc replicas of popular coins. There may have been other companies making such replicas. These reproductions are extremely common and have very little value. Other large pioneer gold coins have been similarly reproduced, but this one seems to be one of the most common. The most common of these has TRADING misspelled as TRACING. Blake and Co $20 gold tokens are even more common.'