An important part of the parish economy, aside from its four manor houses, 48 houses were on Moor and Sheep Lanes in Harmondsworth.
In 1586 land on either side of the river was charged with the upkeep of Mad Bridge, which carried the Bath Road across the river.
Parliament's Act of common land inclosure (privatisation) came to Harmondsworth parish in 1819; in it Harmondsworth's three open fields and Harmondsworth Moor and a big tract to and around Heathrow (part of Hounslow Heath) were divided among the local residents.
During this Enclosure two bad bends of the Bath Road in Longford were straightened.
Many of its buildings are included in the Longford Village Conservation Area, which was designated in 1988 with a minor boundary change in 1999.
It includes seven listed buildings, one listed wall and a number of unlisted properties which are considered to make an important contribution to the character and appearance of the Conservation Area.
Limited evidence survives of Roman occupation, though archaeological excavations have revealed two brooches of Roman date.
Longford, the only medieval settlement to grow up along the Bath Road in Middlesex, had 30 inhabited buildings in 1337.
Longford is a village that has never had a church so can also be considered a hamlet, immediately north-west of London Heathrow Airport in the London Borough of Hillingdon, formerly part of Harmondsworth by tithes, land tax, vestry and still by Church of England parish. Longford is 15.8 miles (25.4 km) west of Charing Cross and within the M25 motorway which marks its western boundary with Colnbrook, Berkshire.
The name Longford derives from the two words "long" and "ford", after the wide ford across the Colne which is where the old Bath Road crosses it, a middle ditch, and the Wraysbury River, carrying on west from the village street.
In the same year the Fairey Aviation Company opened an airfield, the Great West Aerodrome, southeast of Heathrow village.