It is a viola aka violet.* Hard to say if it's a native or a European one that has escaped without something to compare it with.* I have the non-natives in my yard and it seems the leaves are a darker green.* I think I gave you several sites to search for natives in your state.* Look up violet and viola to see if those are native.* You'll have to compare leaf shape, color, where the veins in the leaves are and the color of the flowers.
I'd love to know if you find out.
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.