And here we have another little bit about market hunting:
As the states became populated, market hunting developed into both a major business and a respected profession. With the development of the country, needs for specialized skills developed in the society. Shopkeepers, blacksmiths, doctors, wagon makers, and other craftsmen concentrated on their trades. While they may have enjoyed hunting as a personal activity, they could not afford to hunt for subsistence. One of the developing trades became market hunting. Market hunters provided a supply of wild game meat to the growing towns. These professional hunters specialized in their trade as well, making a living by hunting, trapping or otherwise providing meat.
Skilled specialists, market hunters were not restricted by bag limits or seasons in most states. As a result, their unrestricted harvests were able to deplete game populations significantly. Those impacts were enhanced by habitat loss. One state that was nearly completely forested in colonial times had only 16 percent of its forests by 1850. With the loss of that forested habitat came the loss of most forest and forest edge wildlife.
Although today we know that market hunting led to over-exploitation of many species, market hunters provided a necessary service. Immense game herds and flocks seemed limitless, but as demand for meat and market hunting efficiency increased, populations began to suffer. Obvious declines or even extirpations of deer, bison, antelope and elk took place. Waterfowl and upland birds, including the passenger pigeon, declined under continuous demand for game meat by the growing American population.
As these losses became obvious to sport hunters (non-commercial hunters), they developed a concern for the future of wildlife and began to work for change and improvement. As the end of the 19th century approached, sportsmen conservationists who recognized something was wrong began to call for controls on the harvest of game. They demanded that action be taken to conserve wildlife populations. In 1888, a group of sport hunters started the Boone and Crockett Club, which led a crusade to protect the nation's troubled game herds. Their actions led to the development of national parks and wildlife refuges as well as regulation of harvest. By 1900, twenty-three states enacted laws that limited harvest.
Their efforts started a trend of caring for wildlife that continued into the 20th century as more game protection programs were implemented. In 1900, the Lacey Act prohibited interstate shipment of illegally killed wildlife. This provided some federal help under the interstate commerce clause of the Constitution to control market hunting. A forester at the University of Wisconsin, Aldo Leopold, wrote the first wildlife management text in North America in 1933 and helped formalize the emerging art and science of wildlife management. The Duck Stamp Act of 1934, lobbied for by waterfowlers, provided funds from federal stamps to aid in waterfowl management and to permit purchase of lands for federal waterfowl refuges. Sportsmen lobbied for an additional excise tax on sporting arms and ammunition to provide aid to states for resident wildlife management. In 1937, the Pittman-Robertson Act was passed taxing long guns and ammunition for this dedicated purpose. This legislation has perhaps had the greatest impact on wildlife research and management of any legislation ever passed.
http://www.gunmuse.com/Blog/Dr%20Jim%20Knight/218