http://historyexplorer.si.edu/rss?key=resourcesSmithsonian's History Explorer Resources Related To Book "Rachel Carson and Her Book That Changed the World"http://historyexplorer.si.edu/resource/?key=3179http://historyexplorer.si.edu/resource/?key=3179<p><strong>The Environmental Movement</strong></p> <p>This button depicts the ecology symbol, a small letter &ldquo;e&rdquo; inside the larger letter &ldquo;O,&rdquo; the letters standing for &ldquo;environment&rdquo; and &ldquo;organism.&rdquo; Cartoonist Ron Cobb invented the symbol in 1969. The ecology symbol appeared in a green U.S. flag for the first time in the April 21, 1970 issue of <em>Look</em> magazine.</p>Tue, 16 Apr 2013 10:47:30 GMT