Blackett became a member of the Merchant Adventurers' company of Newcastle-upon-Tyne in 1672. He married an heiress in 1674 and at some time after he acquired the estate of Newby Park at Ripon, Yorkshire.
Blackett joined the Merchant Adventurers' company in Newcastle-upon-Tyne in 1672. He married a wealthy woman in 1674 and eventually acquired the estate of Newby Park at Ripon, Yorkshire.