Are my neighbors racially harassing me?

We are a black family living in a predominantely white neighborhood. We just moved in 2 months ago. We chose the neighborhood because it looked "family friendly" and was in a great school district. However, there are a set of neighbors that have cursed our children out and demanded that our children stay out of their yard, yet their kids wander in our yard every day while they drink beers in their garage. The couple decided to write a letter to our HOA and report that our kids play in the street, we live in a cul-de-sac, that I have an unlicensed daycare, I am licenced, and that our kids leave trash in our yard and other people's yard. They are the only neighbors that have complained. My kids never eat outside or leave trash. My other neighbor leaves his trash out for weeks and it blows all over. Our HOA found the charges unfounded and told the couple to lay off. They have now since called the DSS and reported that our 4 year old was outside at 11pm. My kids go to bed by 9. They reported about the illegal daycare. I have my license. They stated that the kids play in the street and are not watched over. I have pictures of their kids in the street and me telling them to move to the side while their parents are no where to be found. The wife has also made comments to my husband that the neighborhood feels "overwhelmed" because we have a large family. We have 9 kids. We also pay all of our own bills and take very good care of them. Before we bought the house, the couple came over asking the owners if they were going to sell the house to us. Once they found out that she was, they stopped their children from coming over and stopped talking to her. I wonder, what can we do to stop this harrassment? I don't trust them and don't want the to hurt my kids!