Biddeford is served by the Boston & Maine railway, and is connected by electric lines with Portland and with Old Orchard Beach, a popular summer resort north of the Saco river.
A permanent settlement was established on both sides of the river about 1630 under the leadership of Richard Vines (1585-1651) and was named Saco.
In 1762 that portion of Biddeford which lay east of the river was incorporated as the town of Pepperellborough, for which name Saco was substituted in 1805.
A tract along the Tunxus (now Farmington) river, called Massacoe or Saco by the Indians, was ceded to whites in 1648, and there were settlers here from Windsor as early as 1664.
The Conway quarries, four in number in 1908, are on either side of the Saco river, south-east and south-west of North Conway; their output is coarse constructional stones, all biotite or biotite-hornblende, but varying in colour, pinkish (" red ") and dark-yellow greenish-grey (" green ") varieties being found remarkably near each other at Redstone, on the east side of the Saco valley.