Here's a good article discussing Cleveland's skyscrapers:

http://www.clevelandskyscrapers.com/

Many of the most architecturally significant buildings are featured here:

 https://www.bluffton.edu/~sullivanm/o...

Cleveland architecture history in the 20th century:

http://www.architectureofcleveland.co...

The two oldest remaining buildings in downtown Cleveland were built in the 1850s, reflecting the massive demolitions that took place to build Cleveland's skyscrapers, especially what now is known as the Tower City complex.

http://www.clevelandareahistory.com/2...