http://www.google.co.uk/search?q=”middle+class”&hl=en&lr=&prmd=imvnsub&source=lnms&tbm=nws&sa=X&ei=3wkDUJrTDMqE0QHctozsDw&ved=0CFMQ_AUoBA&biw=1064&bih=750&cad=cbv&sei=7QkDUOXVOcrq0gHzpcGhBw#q=%22middle+class%22&hl=en&lr=&prmd=imvnsu
On above ‘advance google search’ link - go to news search and put in date parameters...1800’s to 1960, etc.