Disclaimer: This is just a guide to give you an idea of what your coin might grade. Often coins will grade higher on one side vs. the other. In example, it's possible for a coin to grade G4 on its obverse, but grade VG8 on its reverse. Also, this guide is not a claim that one's coin will obtain any grade listed if submitted to a third party grading service.
Early U.S. Coins were plagued with poor planchets, inconsistent striking pressures, and other variables that effected the details of the coin. Many examples, with only a slight amount of wear, have such weakness of strike that they appear a lower grade to the untrained eye.
So as you view the photos remember that certain high points are consistent with each coin type and should not be counted as wear or loss of metal form being passed hand to hand.
You will notice in the images below that the eagle's breast and liberty's hair suffered from poor striking pressure.