Lewis wrote very little, even letters, and when he was required to address the watercolourists as their president at a dinner in 1855, he stood up and after a while sat down again without saying a word. Partly as a result of the absence of sources, no full biography was published until 2014. Lewis continued to paint and exhibit almost up to the end of his life, but in 1873 he seems to have suffered a crisis in his health from which he never recovered before his death in 1876. After being largely forgotten for decades, he became extremely fashionable, and expensive, from the 1970s and good works now fetch prices into the millions of dollars or pounds at auction.