Different types of locos

[noncngdriver]

Hello! I am currently doing homework to build my own model railroad. I'm learning about track, locos, and rolling stock. I saw either here in this web site or on another site, pics of locos from the 1st steam engine to the current diesel. I didn't mark the page and now can't seem to find it! Without actually putting a name on the engines; (Santa Fe), can you show me a graduating class of engine from 1st steam to current diesel?
          Thank you,
                        Aaron

[RAM]

When you are doing your homework, think small.  Small steam locomotives like a 4-6-0 and 2-8-0s.    A  GP7, GP9 or RS3.

[ebtnut]

Aaron:  Try this link for info on steam loco development:  http://www.trainweb.org/tusp/back.html

[full maxx]

very interesting reading