Congratulations on taking good care of your maple tree. It certainly is healthy to be so young and already have reached the top of the house. It is great that you are also watching your tree for early signs of any problems.
If you want to try to identify your maple tree (if it is a native one), you can look at our website for the Acer genus (maples) to match leaf shapes, tree size and form. We have 27 species and varieties of maples listed.
The wet summer you have been having in North Carolina could be the factor that has caused a fungus disease to attack maple trees (more than other years). This disease is anthracnose and causes v-shaped, brown or tan patches (necrotic areas) to form on the leaves in between the veins and ultimately the leaves to fall prematurely. There are some good images of leaves infected with anthracnose at the Connecticut Agricultural Experiment Station factsheet on Common Diseases of Maple for you to compare with your tree. Other leaf diseases are included as well.
For many fungus diseases that attack trees it is important to rake up all the fallen leaves so that the fungus spores do not overwinter on the soil surface and reinfect the tree the following year. Usually this is enough to keep the disease under control.
If your early falling leaves continue to progress and the health of the tree is a concern, it is suggested that an arborist be consulted.