This often involves me searching for their exact locations, using the excellent http://pubshistory.com/LondonPubs site.
I've got to 110 venues so far in London, just from the 1841-2 advertisements and reports in the Northern Star.
I also try to find out if the pubs are still there (rough estimate is that 10% of them are still in business, using the same name or similar).
Here are a couple I've found which have interesting later histories:
The Sugar Loaf, 187 Hanbury Street, Mile End = Chartist meetings in 1842; anarchist meetings in the 1880s:
The Horns Tavern, 1 Crucifix Lane (already scary!), Bermondsey = Chartist meetings in 1842; haunted pub in the 1960s (now a Thai restaurant):
The Pavilion Theatre, Baker's Row, Whitechapel, was used for benefit concerts.
Here's an article about the area now - http://spitalfieldslife.com/2014/01/12/whitechapels-theatrical-terrace/
The Royal Albert Saloon and Pleasure Gardens, Shepherdess Walk, were also used for benefit gigs.
Here's an interesting playbill from the Museum of London collection - http://www.museumoflondonprints.com/image/415966/beckett-poster-for-the-royal-albert-saloon-1841-1852
and here's an image of a balloon ascent there -
I've mapped all the sites in London, which will be unveiled at the walking tour event at the British Library on 21 September.