sentences:  By 1838 and the opening of the Great Western Railway, Upton-cum-Chalvey's parish population had reached 1,502 - but this was exceeded by the neighbouring parish of Langley Marish (1,797).If Slough was known at all, it was as a source of bricks, and of hotels where visitors to the royal family at Windsor Castle might lodge.The Great Western Railway opened in Slough in June 1838.