He was chief caricaturist between 1799 & 1815 for the leading British publisher South.W. Fores. He worked in a style similar to James Gillray. In his earlier works, Williams used the pseudonyms Ansell or Argus.
With George Cruikshank and others he illustrated The Every-Day Book by William Hone, edited 1825-1826.
Williams was the first of many who caricatured the 1st Duke of Wellington. He published a drawing of him in September 1808, during the Peninsular War, in which the Duke cuts off the pigtail of French general Jean-Andoche Junot, defeated at the Battle of Vimeiro.