In 2014, I planted beach plum from NH and american plum from Missouri MDC. I planted in an old hay field. They were tubed or caged but have not had weed control. Neither have gotten big enough to fruit yet. I'm sure they'd be a lot farther along with weed control.
Deer and bear would eat beach plum and American plum. For people, both would likely be too bitter to eat and smaller than a European or Japanese plum you would buy at the store. Being seedlings, some might turn out better tasting than others. Both would make good jelly and jam. Some nurseries sell improved beach plum seedlings. American plum is probably the better choice for wildlife as it has thorns to limit browsing. Beach plum does not have thorns.
+1 to what chickenlittle said about seedlings - some might be better than others. Not all of my American plums from MDC are producing yet, but of those that do, I have eaten one that was very good. These look awesome, but are both sour and bitter. Doesn't stop the critters from keeping them cleaned up as they fall from the tree, which was mid through late September for this tree.
I have 2 or 3 plum trees that bare small fruit but i'm not sure which they are ! They seem to be darker in color than the ones shown in the pics here ! They have been here since I bought the land which use to be an old farm stead ! I also have 2 sickle pear trees !