Alexis-Charles-Henri Clerel de Tocqueville (French: [aleksi SaRl aRi kleRel d@ tokvil]; 29 July 1805 - 16 April 1859) was a French political thinker and historian best known for his works Democracy in America (appearing in two volumes: 1835 and 1840) and The Old Regime and the Revolution (1856). In both of these, he analyzed the improved living standards and social conditions of individuals, as well as their relationship to the market and state in Western societies. Democracy in America was published after Tocqueville's travels in the United States, and is today considered an early work of sociology and political science. Tocqueville was active in French politics, first under the July Monarchy (1830-1848) and then during the Second Republic (1849-1851) which succeeded the February 1848 Revolution. He retired from political life after Louis Napoleon Bonaparte's 2 December 1851 coup, and thereafter began work on The Old Regime and the Revolution. He argued that the importance of the French Revolution was to continue the process of modernizing and centralizing the French state which had begun under King Louis XIV. The failure of the Revolution came from the inexperience of the deputies who were too wedded to abstract Enlightenment ideals. Tocqueville was a classical liberal who advocated parliamentary government, but was skeptical of the extremes of democracy. 
How long was Toquville active in french politics?
From 1835 to 1840