Bingo! I think you have figured it out. It definitely looks like a Hawthorn. I bet one of our many bird visitors transplanted it by droppings. I think that I will keep it since the wildlife seem to enjoy it, but maybe I can try moving it to a different area of the yard since it is very close to my walkway right now. Thanks so much for the help!

You have a beautiful home. When it was built , the builder had a plan to follow. You should have one for the foundation plants as well. The plan will allow you and someone that has expect plant knowledge to select the right plant for the right spot. The camellia bushes are a good example. Also someone with an eye for design, may suggest a more curvy bed design, plants of different height, texture, and different bloom times. There are many options for obtaining professional help. Some garden centers will provide a design, and then you buy the plants from them, there are many landscape designers that will sell you a design and you plant DIY ( saving you the cost of labor) And I am sure there will be many suggestions here on this forum. Next - We will be able to provide the best help, if you identify where the home is located ( exact address not needed) . For example, (Central PA , zone 6) also does the house face N,E,W,S ? And how much sun/shade (hrs) does the front get. Also how high are those windows from the ground..... The photos are really good, but we will need more. Regarding the non-blooming forsythia by our mailbox. Did you plant it? do you know what type of forsythia this is ? Most forsythia I am familiar with get about 8x8, so the location is not ideal. Also did you prune and when? Best to prune in the late spring after the regular bloom time. Otherwise you may have pruned the blooms if you punned too late. Enjoy you beautiful home ! Garden Design Ideas Mike L

Thanks, Embothrium. I kept reading that poison ivy/oak leaf clusters come in threes, but I wasn't sure if that was 'tip of plant only' or all the way along the vine. This pic (poison sumac) looks very similar to my pics, which is why I worried it might be that:

Ampelopsis arborea. https://www.discoverlife.org/mp/20p?see=I_TQBH752&res=640&flags=glean: I see it has had a name change and is now Nekemias arborea. http://forestry.sfasu.edu/faculty/stovall/dendrology/index.php/fact-sheets-sp-916/photographs/253-ampelopsis-arborea-peppervine