2000 Market Street in Philadelphia is an example of International style architecture in that city from the early 1970s.  Completed in 1973 by architect.  It has a same gray-black, obelisk look.

    The John Hancock Center in Chicago is 100 stories, and was finished in 1969.  Engineer Fazlur Kahn utilized a comparable frame-tube system as in the Sears Tower.  The architect was Bruce Graham from Skidmore, Owings & Merrill.  It is 1,127 feet high.  The outside "x" bracing avoids the need for interior support beams.