I’m a little embarrassed that I spent hours on this, but it was a great experience! 
I spent roughly an hour struggling to make the outer step-lining because at some point I accidentally hit “o”. I didn’t know that was a shortcut key for turning on proportional editing (everything moving with my grabbed face, edges, and vertices. I feel so silly for struggling against instead of acknowledging I may have turned on a new setting that could interfere with my editing.
(This link helped me realize my problem: http://blender.stackexchange.com/questions/27394/why-cant-i-transform-faces-edges-or-vertices-without-transforming-the-whole-o)
P.S. I didn’t realize the challenge was for a much simpler structure for this challenge, until after I had created the stairs. 
