Hamersley's family estate was at Pyrton Manor near Watlington, Oxfordshire, but he rose to prominence in London as a merchant.
The first plans for the Cholsey to Wallingford line date from 1861, and envisaged an independently owned route from Moulsford to Princes Risborough via Wallingford, Benson, Watlington and Chinnor.
The Watlington and Princes Risborough Railway was a railway branch line between Watlington and Princes Risborough which remained operational for over 88 years between 1872 and 1961.