My John P. Brower and Hannah Halstead were married in Buffalo, Erie County, New York in 1816. Newspapers.com, Buffalo Gazette. In the 1840 federal census they are living in La Beouf, PA. They were selling property owned in Erie County, PA during that time as well. A DNA cousin provided this reference: From Early Settlers of New York State: Their Ancestors and Descendants, Volumes I-VI (PART II - iv-vi), page 270 (https://books.google.com/books?id=jTduA7gtMxgC&lpg=PP1&a...
I notice that Brower often gets transcribed as Brown. John P. BROWER, son of Matheus Brower and Catrena Van Wert, is NOT a Brown. He is descended from Adam Brouwer, one of the earliest Dutch Brouwers. This is not the same family that you are looking for.
John P. BROWER and his wife Hannah, had Emily, Ephraim, Clarissa, Alfred, Thomas and George. Thomas is my 2nd GGF. He came to California in 1852 for the Gold Rush.