The blooming flowers of the hop plant have been crucial to the beer brewing industry since ancient times. In the UK, hops are grown mainly in the Kent region. When harvest time came, there weren't enough local laborers to pick the blossoms, so poor families from London made a pilgrimage every year to pick hops and pick up some extra cash.
By 1870, special trains were being run to transport families to the hop fields. Londoners who could not afford to get out into the country normally looked on harvest time as something of a holiday.
On arrival, though, conditions were squalid. Families lived in barns, tents, stables, even pigsties. Hygiene was poor and disease spread — in 1849 cholera killed 43 hop pickers on a single farm.
In the 1860s, two priests began to visit the hop fields and campaign for improved conditions, eventually forming the Society for Employment and Improved Lodgings for Hop Pickers in 1866.
Whole families worked to pick hops, while only men wore stilts to reach the highest of the vines. The tradition of traveling to Kent to pick hops died out in the 1950s with the arrival of automated picking machines. See a gallery of photographs from the days of the hop pickers at Retronaut. -Thanks, WTM!