The 2-6-0 wheel alignment was popular from the 1860’s to the turn of the century. Baldwin was the biggest producer of 2-6-0 which American Rail says is synonymous with the Mogul. Alco likely did not manufacture many 2-6-0 locomotives as the company was not formed until 1901. However, the companies that merged to form Alco did manufacture 2-6-0s from its earliest days. Over 11,000 Moguls were manufactured in the US from 1860 to 1910.
The American Locomotive Company was formed in 1901 by the merger of Schenectady Locomotive Engine Manufactory of Schenectady, New York with seven smaller locomotive manufacturers.
The other companies that merged were Brooks Locomotive Works in Dunkirk, New York, Cooke Locomotive and Machine Works in Paterson, New Jersey, Dickson Manufacturing Company in Scranton, Pennsylvania, Manchester Locomotive Works in Manchester, New Hampshire, Pittsburgh Locomotive and Car Works in Pittsburgh, Pennsylvania, Rhode Island Locomotive Works in Providence, Rhode Island, Richmond Locomotive Works in Richmond, Virginia.
Two notables 2-6-0 trains are still in operations: Walt Disney World Railroad (WDWRR) no. 2 Lilly Belle, built in September 1928, operates on the railroad circling the Magic Kingdom in Orlando, Florida since 1 October 1971. See Video https://www.youtube.com/watch?v=3qEqCWahSAM
Also Everett Railroad no. 11 operates tourist trains on the Hollidaysburg, PA-based shortline. See Video https://www.youtube.com/watch?v=d_CB9eyZvRc
Everett Railroad No. 11
The Everett Railroad No. 11 was built by Cooke Locomotive an Alco company. For more information about the train go to http://www.everettrailroad.com/railfans/11.aspx
Boston and Maine Railroad has some great images of 2-6-0 locomotives built by companies that formed to make Alco including Manchester, Dickenson, and the Rhode Island Locomotive Works https://sites.google.com/site/bostonandmainerailroad/home/boston-maine-steam-locomotives
For more information about the Canadian National No. 409 go to http://search-bcarchives.royalbcmuseum.bc.ca/canadian-national-railway-2-6-0-no-409-mogul-port-mann-yard
For more information on Pennsylvania No. 9684 see the textbook Guide to Narrow Gauge Modeling.