Rock Island Overview

BRHS posted
The first train on the Chicago & Rock Island Railroad was operated on October 10, 1852, between Chicago and Joliet, Illinois.
Its predecessor, the Rock Island and La Salle Railroad Company, was incorporated in Illinois on February 27, 1847, and an amended charter was approved on February 7, 1851, with construction beginning in Chicago on October 1, 1851.  Construction continued on through La Salle, and Rock Island was reached on February 22, 1854, becoming the first railroad to connect Chicago with the Mississippi River.
Michael Riha's post has the same comment

Tucumcari, NM, was where the Golden State passenger train interchanged between the SP and the Rock Island. The Golden State ran between Chicago and Los Angeles.

Jack Robertson posted

"While the Rock Island had many glory years, it was caught up in a cycle of competition, excess capacity, flat revenue, and increasing costs in the decades after World War II. The railroad attempted to merge with the Union Pacific in the 1960s, but every other Midwestern railroad filed protests over the proposed merger. The merger was finally approved in 1974, but by that time, the railroad had deteriorated to the point where Union Pacific was no longer willing to make the investment to keep it running. The Rock Island attempted to continue operating. It finally collapsed after a strike all but stopped the trains in August, 1979. The courts rejected the bankruptcy reorganization plan in early 1980, leading to the liquidation of the company." [John A Weeks III (I lost the link reference)]

 

Dan Sabin posted
1932 Rock Island Freight Density Map
[I wish this was higher resolution.]

One of twenty images posted by Cam Aulds from an article about the "Last days of The Rock."

Andy Kowalxzyk posted
"The Great Rock Island Route" (original version of "The Wabash Cannonball")
Sheet Music and route map
 https://levysheetmusic.mse.jhu.edu/collection/057/135
Larry Candilas: The Rock Island went to Milwaukee? [That caught my eye as well.]
Harold J. Krewer: That line into Wisconsin was the Racine & Southwestern, which actually got built and ended up part of the Milwaukee Road. Wasn't abandoned as a through route until 1980, Davenport-Savanna and east to Kittridge, IL (SW of Freeport) is still active as part of the CP's Chicago-KC route.
Ned Carlson: Harold So The Rock had some through car or trackage rights arrangements on the route?
It must have been taken over by the CM&StP pretty early, that's why the street in front of what was the Beloit station is called St Paul Ave.
I'd give my other front tooth to see a photo of a Rock engine or train in Wisconsin.
Harold J. Krewer: In the late 1800s, it was not uncommon for competing railroads to embellish their magnitude and reach by advertising and promoting friendly connecting roads as part of their "system," even if no formal ownership or control existed.

Ross Warnell posted
I have a question. It has been said Rock Island went everywhere its competition did, but the long way around (St Louis - Kansas City). What, then, was the rationale for that long north-south line from Little Rock to Eunice, Louisiana. Other than the Southern Arkansas oil boom in the 1920's, I can't think of any reason at all.

Bill McCord: CRIP had some good routes. A Chicago-Memphis and Little Rock -Dallas route would have been helpful. Given all the lines that survived that are now main lines it is too bad the Rock didn’t survive. The Memphis- Tucumcari line should have been saved.

Keith Pomroy: Bill McCord as stand-alone major railroads, the Midwestern grangers (Rock Island, Milwaukee, Northwestern, and Burlington) were facing problems in the 1960s in both raising enough capital or earning enough to cover capital needs—maintenance and modernization, mostly—to provide both a dense network of agricultural branches AND a set of fast and productive mainlines. Merger with transcontinental connections was deemed the answer, and that worked well for the CB&Q. The C&NW was able to diversify into reasonably profitable other industries, while keeping the railroad going. The Milwaukee began radical retrenchment in the 1970s by scaling back on its electrification and then altogether on its Pacific Extension (which was unable to match BN or subsidize the branches). The UP and SP wanted the Rock, but ICC dithering and connecting railroad opposition delayed things so long that by 1975, there was little hope.

Bill Pollard: The original plan for the line extending south of Little Rock was to reach New Orleans.

[There are a lot more interesting comments on this post. Too many to try to copy.]