As early as 1829, when battle was first joined to prevent building, a writer from Gray's Inn stressed the need for all classes to escape from noise and dirt to one of the few remaining 'lungs of the metropolis'.
His hope that a public asset might be preserved, if only for the sake of private rights, found support in the House of Commons and in a well known cartoon by George Cruikshank, showing the advance of bricks and mortar.
The general good was again emphasized in 1844: Lord Chief Justice Denman, supporting the local property holders, declared that thousands of Londoners daily enjoyed the heath during the fine months.
The claim was perhaps exaggerated.
Eighteenth-century races had presumably attracted outsiders but many early sporting contests concerned only local or visiting teams.
Parties, opposed to individual walkers, may have been drawn more by the inns and pleasure gardens than by The Heath itself.
Donkey riders, numerous from the 1820s or earlier, were often shown as middle-class in the 1850s.
There were also, however, crowds of humbler visitors and even all-night revellers.
Together with riders and picnickers, they had attracted cartoonists before the Hampstead Junction railway made The Heath accessible to thousands of poorer families who lived beyond walking distance.
The opening of Hampstead Heath station in 1860 assured The Heath's future as a playground for London's East Enders.
There followed yet more published accounts and illustrations of popular pastimes, including copies of Watkin Williams's song 'Hampstead is the Place to Ruralise' c. 1863.
An informal fair presumably had already benefited from the closure in the 1850s of Bartholomew, Camberwell, and Greenwich fairs.
It was held near the Vale of Health, where the first hotel was built in 1863 in order to profit from the crowds brought by the railway.
The trend was encouraged by Sir Thomas Maryon Wilson, who, in his campaign against the gentry, licensed an ice-cream vendor to build a wooden refreshment room at the foot of Downshire Hill in 1861 and assigned a large site for a fair ground in 1865.
The writer William Howitt complained in 1869 that Sunday evening revellers swarming homeward down Haverstock Hill could be heard from his house in Highgate.
Such popularity was perhaps decisive in the parliamentary battle to prevent building.
Acquisition as a public open space was followed closely by the Bank Holidays Act, 1871, which created three holidays in months when it was possible to enjoy the heath.
Enormous crowds gathered, as on Whit Monday 1872, when the fair covered the whole of East Heath to Spaniard's Road, from which height carriage visitors could look down on the working class at play.
Damage, particularly fires among the furze, and rowdiness were often a problem in the 1870s, when there might be 30,000 visitors at the August holiday and 50,000 on a fine Whit Monday.
Violence was also a problem at the bonfires and processions held from before 1850 on Guy Fawkes day, until in 1880 a committee was set up to regulate them.
Numbers reached 100,000 in the 1880s, although that estimate for 1880 included trippers to Parliament Hill Fields, which were not yet part of The Heath.
The crowds were thickest in the south-east corner near the station, where in 1892 nine people died in a rush to escape from the rain.
'Appy' Ampstead became a nationally known phrase in the 1890s, when celebrated in a song by Albert Chevalier and in the cartoons of Phil May.
The Heath was the L.C.C.'s most popular open space in 1899 and bank holiday pleasures at other London parks were mere 'modifications' of those at Hampstead in 1901.
The scene had grown more respectable by 1910, when there were fewer assaults and thefts at what had become gigantic children's parties'.
Attendance records were broken on Easter Monday, always the heath's busiest day, with an estimated 200,000; on the following August holiday, 50,000 came by railway alone.
In 1920 Queen Alexandra drove slowly by, to view Easter Monday's 'traditional festivities and licence', and promenaders still thronged Spaniard's Road on a fine Sunday.
The public acquisition of The Heath in 1871 ended more than forty years of uncertainty.
Sir Thomas Maryon Wilson, restricted by his father's will to granting leases of no more than 21 years on his Hampstead property, sought wider powers through successive estate Bills, all of which were defeated.
His proposals alarmed substantial local residents, who successfully presented them to a wider public as threats to an increasingly popular Heath.
The battles in the press and parliament left Sir Thomas, a stubborn and irascible man, with a long lasting reputation as a would-be despoiler.
Only in the 1970s, in the most detailed account, was it pointed out that Sir Thomas was singularly unfortunate in meeting such powerful opposition.
His story showed the rights of property, at a time when they were normally paramount, being overridden in the name of the public interest.
It also showed how motives could be disguised by confusing the issues of the copyholders' rights, the lord's freehold, and public enjoyment of The Heath.
Sir Thomas's first estate Bill was withdrawn from the House of Commons in 1829, after local opposition and a campaign in the press on the need to preserve open space.
In reality his desire to obtain the power to grant 99-year building leases on all his Hampstead lands did not arise from plans for The Heath as it then existed, where the copyholders could insist on their rights of pasturage, but for his 60 acres of exclusive freehold which were later known as East Heath Park or East Park.
Building there, along the St. Pancras boundary, would have hemmed in The Heath and threatened the views of many Hampstead gentry and of Lord Mansfield from Kenwood.
Lord Mansfield therefore joined the opposition and in 1830 helped to defeat a second, modified, Bill in the House of Lords.
It was probably the House's first division on an estate Bill, all the more notable for taking place in an unreformed parliament.