There was an Alexander Mears who married Jane or Jeanne McCauley in March 1794. I am descended from Jeanne's sister, Margaret, who married John Hanna and settled in Tioga County, NY.
Obviously, I am a 'far flung' relative, but I've been digging into the McCauley tree, as Jeanne's and Margaret's father, Alexander McCauley, disappeared mysteriously while out looking for his cattle. They all lived in the Roaring Creek Valley (Berwick, Nescopeck, etc.).
Alexander Mears was the eldest son of Samuel Mears. According to The History of Columbia and Montour Counties, Pennsylvania by J. H. Battle, 1887, Locust Township. This Samuel Mears came to Philadelphia in 1769, according to this source.
Perhaps you already have this info, but I thought I'd put it out there for you! Happy hunting!