As a delegate to the 1969 Illinois constitutional convention, Frank Cicero Jr. has a special perspective on the importance of the six constitutional conventions in Illinois’ history.Cicero’s new book, “Creating the Land of Lincoln: The History and Constitutions of Illinois, 1778-1870,” delves into the prominent issues debated by delegates at four of the constitutional conventions, which led to the state’s first three constitutions.“Constitutions are very, very important documents …