chicago former u.s. president barack obama wednesday unveil design plan chicago presidential center hop serve train site future generations leaders obama presidential center build 500-acre 200-hectare jackson park chicago south side park first develop site 1893 world fair development feature three build museum forum library form campus around plaza museum tall three structure include public areas offices classrooms addition exhibition space obama foundation say statement want world premier institution train young people leadership make difference communities countries world goal obama say design unveil chicago obama slowly start return public eye since leave office january last month moderate event university chicago first major appearance since leave white house project take around four years complete obama say educational program begin year obama say wednesday would donate million summer job program community obama grow hawaii go college new york california own home spend pre-white house political career chicago start community activist become illinois state senator u.s. senator chicago beat proposals new york city hawaii home library tod williams billie tsien architects partner new york interactive design architects chicago name last year firm lead design center residents chicago south side include many poor crime-ridden neighborhoods hope job investment come library small businesses concern may force area rental price go center could transformational project community obama say obama detail plan chicago presidential center