The following was extracted from 1886 book. Probably not relevant. Any Philips in the Montague clan I have come across seem to come from County Siigo or Co Leitrim.
473. Philip Montague, of Keep Trust, Washington Co.. Md. For years he worked in the Armory at Harper's Ferry. It is thought that he died and was buried there.
DESCENDANTS OF PETER MONTAGUE. Married, Mary McWilliams, and had twelve children. The names of seven only were given.
CHILDREN. 474. James Stephen, b. in 1831. 475. John, b. 476. Joseph, b. 477. Susanna, b. ; m. a Mortimer ; he was a postmaster of Keep Trust, Washington Co., Md. 478. Sarah, b. 479. Martha, b. 480. Mary, b.twins
474. James Stephen Montague, son of Philip (473), b. in 1831, the eldest of twelve children. Trade, a machinist. Resides, 256 Third Street, San Francisco, Cal. Married, Jane Dougherty, who was b. in the North of Ireland.
CHILDREN. 481. Philip, b. March 24, 1868. 482. Edward, b. Jan. 26, 1872. 483. John, b. Feb. 14, 1874.