I have both Walkers and Harpers in my ancestry. William Harper Walker b. 1825 in NY after his parents immigrated from England; died in Gillette, MO in 1866. His wife was Elizabeth or Mary Elizabeth. Two children Byron and Cora. Do you have anyone like that in your tree? I didn't find your names in mine.
Parents were James Walker, Elizabeth Harper. (Seaton Ross, Yorkshire england) Elizabeth's parents were William Harper and Barbara Holmes. She had a half brother William Harper (son of Wm and Jane) wife Margaret.