In general,
If they are from a hatchery, even if they aren't listed specifically as "Commercial" but are listed something like "Our Best Egg Layers" etc, they are going to be commercial type birds bred to lay a lot of eggs (500 seems to be the standard) in the typical commercial cycle, which generally includes replacing them around 2.5 years old. These usually include the White Leghorns, RIR, and the various Red Sex Link crosses. Many popular breeds from hatcheries are also headed this way as hatcheries primarily select birds on who lays a lot of eggs for their breeding stock, Buff Orps, BR, a lot of the hatchery EEs/Ameraucanas etc. Remember a hatchery is a business and needs to make money, and they need chickens that lay as many eggs as possible in as short a time as possible. They are not selecting chickens on the basis of a long life, or for laying for a longer period of time, even if the # of eggs winds up the same.
Your most "Natural" chickens would probably be your wild jungle fowl types, they lay a couple dozen eggs a year.
You are probably going to want to look into "Heritage" birds, in many cases they maybe the same breeds that are found in hatcheries, but they have been bred for and selected for different things. (iow, a Heritage White Leghorn is going to be quite different from a Commercial White Leghorn). These usually come from private breeders. The American Livestock Breed Conservancy's link and definition is below.
http://www.livestockconservancy.org/
ALBC's newly released definition for Heritage Chickens: Standard breeds of chickens as defined by the American Poultry Association that are naturally mating, long-lived, and slow growing.
According to the definition:
The Heritage breeds must reproduce without the assistance of artificial insemination. While artificial insemination is not currently used for commercial chicken reproduction, it is very possible for chickens to follow the same path as industrialized turkeys, which are now reproduced exclusively using artificial means.
Heritage hens should actively reproduce for 5-7 years and roosters for 3-5 years. This is unheard of in commercial production where hens and roosters are used for breeding for a single generation before being dispatched as less than efficient.
Heritage Chickens are also slow growing by modern commercial standards, taking 16-18 weeks for Heritage Chickens as compared to 6 weeks for an industrial breed to reach a dressed (packaged) weight of 3 pounds.
According to the ALBC, chickens have been a part of the American diet since the arrival of the Spanish explorers and since that time, different breeds have been developed to provide meat, eggs and pleasure.