In 1796-1798 he took lessons from John Thomas Smith and later from George Frost, who supported his love of landscape painting and encouraged him to study Gainsborough's works. In 1700 he entered the Royal Academy Schools. As a student he copied Old Master landscapes, especially those of Jacob van Ruisdael. Though deeply impressed by the work of Claude Lorrain and the watercolours of Thomas Girtin, Constable believed the actual study of nature was more important than any artistic model. He refused to "learn the truth second-hand". To a greater degree than any other artist before him, Constable based his paintings on precisely drawn sketches made directly from nature. His most notable picture of his early works are Dedham Vale (1802), 'A Church Porch' (The Church Porch, East Bergholt) (1809), Dedham Vale: Morning (1811), Landscape: Boys Fishing (1813), Boatbuilding (1814), Wivenhoe Park (1816), Weymouth Bay (1816). Flatford Mill (1817) was his last work of the period, created en plein-air.
He married Maria Bicknell in 1816 and they settled in London. After 1816 he changed the method of his work turning away from realistic agrarian landscapes such as Landscape: Ploughing Scene in Suffolk (A Summerland) (1814). Now he was working mostly in his studio in London and had to work out the image from his memory, starting each picture from a full-size sketch. The sketches enabled his memory to develop gradually until everything he could remember about the scene was satisfactorily suggested. At this point he would begin the finished painting. Each of his large canvass starting with The White Horse (1819) and continuing through Landscape: Noon (The Hay-Wain) (1821), The Lock (A Boat Passing a Lock) (1824), The Leaping Horse (1824-1825), The Cornfield (1826) was fulfilled in this way.
Although he never was popular in England, some of his works were exhibited in Paris and achieved instant fame. In 1829 he was finally elected a Royal Academician. His other important works of these period were Hampstead Heath (c.1820), Salisbury Cathedral, from the Bishop's Grounds (1823), A Mill at Gillingham in Dorset (Parham's Mill) (1826), Dedham Vale (1828), Hadleigh Castle (1829), Old Sarum (1829), Salisbury Cathedral, from the Meadows (1831). He died on 31st of March, 1837 working on his last picture Arundel Mill and Castle (1837).