Many accurate 1921 census transcriptions have already been added to the pub history site, including London, and parts of Middlesex.
Aldgate pub history index
Existed from at least 1762. This address appears to have disappeared by 1882. I think there is a strong chance that this is the pub that earlier had the address Salt-Petre Bank. ** This is at or by the Carron and the Black Lion & Carron Wharves.
Residents at this address.
1762/[Black Boy, Salt-Petre Bank] Thomas Evans/../../../Proceedings of the Old Bailey **
1 April 1789/Insured: William Barton, the Black Boy, Lower East Smithfield, victualler/../../Sun Fire Insurance records at the LMA
9 October 1794/Insured: Charles Wipperman, The Black Boy, Lower East Smithfield, victualler/../../Sun Fire Insurance records at the LMA
1794/[Black Boy, Lower East Smithfield] Charles Wipperman / Victualler /../../Sun Fire Office records held at Guildhall Library **
1833-34/John Corsan, Black Boy, 88 Lower East Smithfield/../../Pigots Directory
1839/George McBlain/../../../Pigot�s Directory **
1841/George McBlain/../../../P.O. Directory **
1841/Mary McBlain/Publican/45/../Census
1841/Stephen Larkins/Mariner/50/../Census
1841/Edward Stephens/Clerk/30/Middlesex/Census
1841/Henry King/Mariner/25/../Census
1841/William Freeman/Miller/40/../Census
1841/Sarah Junks/Independant/55/Middlesex/Census
1841/Ellen Carter/Female Servant/20/Middlesex/Census
1841/Will Reading/Male Servant/15/../Census
1842/George McBlain/../../../Robson�s Directory **
Morning Advertiser 05 July 1847 - Transfers
Black Boy, Lower East Smithfield, Henry Watling to Eliza Morley
1851/James Marley/../../../Post Office Directory
August 1853/John Angus McLeod/Outgoing Licensee/../../Era
August 1853/William Brock/Incoming Licensee/../../Era
1856/William Brock/../../../Post Office Directory
1862/James Woollcott/../../../Post Office Directory
1864/James Woollcott, Black Boy, 88 Lower East Smithfield/../../Post Office Directory
7th July 1866/James Woolcott/Outgoing Licensee/../../East London Observer +
7th July 1866/Charles Chessell/Incoming Licensee/../../East London Observer
+
1869/Charles Chessell/../../../Post Office Directory
March 1870/Robert Chesell, deceased/ Outgoing Licensee /../../East London
Observer ***
March 1870/Rosanna Chessell, Widow of Robert Chesell, late occupier/ Incoming Licensee /../../East
London Observer ***
1871/Rosanna Chessell/Licensed Victualler, Widow/39/Plymouth,
Devonshire/Census
1871/Richard W G Walshe/Son/13/Aldgate, Middlesex/Census
1871/Sarah A G Chessell/Daughter/6/Wapping, Middlesex/Census
1871/Sarah Banks/General Servant/24/Bread Street, City/Census
1871/John Long/Lodger, Labourer/54/Ireland/Census
1871/Edward Webb/Lodger, Ship Worker/46/Falmouth, Cornwall/Census
1874/Rosianna Dow Chessell/../../../H.D. Miles London & Suburban Licensed
Victuallers' Directory **
+ Provided by Friends of Tower Hamlets Cemetery Park
** Provided By Stephen Harris