Jenkins began drawing and engraving at the age of fourteen. He travelled a great deal on the Continent and the British Isles during his youth. He became a member of the N.W.S. but left in 1847 to become an Associate, and later a member of the O.W.S. in 1849 and 1850 respectively. From 1850 until his death Jenkins devoted himself to compiling a history of watercolour painting, his notes forming the basis for Roget's History of the O.W.S. His collection and studio were sold in these Rooms, 1 March 1886.