Complex sentence: In May 2013, Chatfield was invited by the National Cartoonists' Society to host the 67th Annual Reuben Awards in Pittsburgh, Pennsylvania and subsequently invited to host the 69th Annual Reuben Awards in Washington, DC in May 2015.
Split into simpler sentences: In May 2013, Chatfield was invited by the National Cartoonists' Society to host the 67th Annual Reuben Awards in Pittsburgh, Pennsylvania. He was subsequently invited to host the 69th Annual Reuben Awards in Washington, DC in May 2015.