Joseph Blackburn ( 1752 - 1778 ) was a British painter. Joseph Blackburn s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 2289.38 USD for Portrait of Colonel Benjamin Pollard (1696-1756). in 2011 to 29520 USD for Portrait of David Mumford (1730-1807), New London, Connecticut in 2017 , based on the size and medium of the artwork.