. ▁In ▁ 1 9 5 7 , ▁in ▁response ▁to ▁the ▁" I ▁Like ▁El vis " ▁button ▁cra ze , ▁C ened ella ▁and ▁Edmund ▁Le ites ▁made ▁the ▁" I ▁Like ▁Ludwig " ▁button , ▁since ▁he ▁listened ▁to ▁Be eth oven ▁a ▁lot . ▁The ▁button ▁became ▁a ▁national ▁s eller , ▁making ▁it ▁in ▁an ▁article ▁of ▁Observ ation ▁Post ▁and ▁a ▁com ic ▁of ▁Pe an uts ▁where ▁Charlie ▁Brown ▁sees ▁Sch ro eder ▁we aring ▁the ▁button . ▁He ▁sold ▁thousands ▁of ▁buttons ▁which ▁with ▁the ▁money ▁he ▁made ▁got ▁him ▁in ▁the ▁Art ▁Stud ents ▁League . ▁C ened ella ▁continued ▁to ▁receive ▁his ▁formal ▁education ▁at ▁The ▁Art ▁Stud ents ▁League ▁of ▁New ▁York , ▁where ▁he ▁studied ▁under ▁the ▁late ▁German ▁sat ir ical ▁painter ▁George ▁Gros z . ▁▁ ▁In ▁ 1 9 8 8 , ▁he ▁took ▁over ▁the ▁George ▁Gros z ▁Chair ▁at ▁The ▁Art ▁Stud ents ▁League ▁and ▁taught ▁three ▁courses ▁from ▁ 1 9 8 8 ▁to ▁ 2 0 1 6 . ▁He ▁was ▁replaced ▁with ▁Gre gg ▁Kre utz ▁and ▁Kre utz ▁still ▁teach es ▁there ▁to ▁this ▁day . ▁ ▁Career ▁▁ 1 9 5 0 s - 1 9 6 0 s ▁Sat ir ical ▁paint ings ▁of ▁pop ▁art , ▁experien cing ▁the ▁death ▁of ▁George ▁Gros z ▁In ▁the ▁ 1 9 5 0 s , ▁C ened ella ▁began ▁to ▁paint , ▁the ▁same ▁time ▁when ▁there ▁was ▁a ▁bo om