Cowboy food often starts with the letter “b” as in bacon, beans, beef, biscuits and bread. “Three B’s” of army life were cited in 1916—beef, beans and bacon. “Four B’s” were cited in 1958—beef, beans, bacon and biscuits.
 
The book A Room for the Night: Hotels of the Old West (1966) mentioned “the four B’s — sourdough biscuits, bacon (called by cowboys overland trout), beef, and beans.” The book Saloons of the Old West (1979) called it the “Basic Four B’s”—sourdough biscuits, beans, beef and bacon. A 1992 newspaper article described the “Three B’s of Old West Cooking”—biscuits, beans and beef.
 
 
29 June 1916, Riverside (CA) Daily Press, “Mobilization Camp Notes” by U.P. Staff Correspondent, pg. 2, col. 6:
Appetites that demanded luxuries and delicacies now have to be satisfied with just plain grub, as, for instance, the “Three B’s” of army life—beef, beans and bacon.
 
Google Books
Arizona Cattlelog
Volume 14
1958
Pg. ?:
The four b’s — beef, beans, bacon and biscuit still tell the story fairly well.
 
Google Books
A Room for the Night:
Hotels of the Old West
By Richard A. Van Orman
Bloomington, IN: Indiana University Press
1966
Pg. 110:
... and the four B’s — sourdough biscuits, bacon (called by cowboys “overland trout”), beef, and beans.
 
23 May 1971, Boston (MA) Globe, “A camper who likes to cook” by Bill Riviere, pg. C7:
This doesn’t mean the monotony of the three B’s - beans, bacon, and biscuits.
 
13 April 1977, Alton (IL) Telegraph, pg. B6, col. 1:
The three B’s are bacon with beans, biscuits
 
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Saloons of the Old West
By Richard Erdoes
New York, NY: Alfred A. Knopf
1979
Pg. 111:
Some people said that western saloon food was confined to the “Basic Four B’s”— sourdough biscuits, beans, beef, and bacon (“overland trout” in cowboyese).
 
Philadelphia (PA) Inquirer
Chuck-wagon Chow Yee-hah! The Three B’s Of Old West Cookin’ - Biscuits, Beans And Beef - Spell Good Eatin’ For Today’s Tenderfoot.
August 09, 1992|By Andrew Schloss, FOR THE INQUIRER
Things western, from wearing apparel to dancing, are pretty hot these days, fueled by the American spirit of freedom, the love of wide-open spaces and Garth Brooks.
 
27 January 1993, Indiana (PA) Gazette, “Party during Super Bowl with authentic cowboy cuisine” by Beverly Bundy (Fort Worth Star-Telegram), pg. 14, col. 2:
But it’s the three Bs that still thrive in Texas cooking. The beef is no longer yesterday’s trail straggler but comes from the neighborhood grocer, wrapped in cellophane; the beans are no longer just kidney or pinto beans, but are just as apt to be black beans of Mexico’s interior; and the bread, depending on which part of Texas is home, is likely to be tortillas or soft Southern-style biscuits.
   
Google Books
Doom, Death & Danger
By Laurie Calkhoven
New York, NY: Scholastic
2004
Pg. ?:
On the trail, cowboys survived on the three b’s — beef, beans, and bread.
 
EVliving.com
2006 FESTIVAL OF THE WEST TO FEATURE THREE CHUCKWAGON AND DUTCH OVEN COOK-OFFS
February 22 , 2006 by Kathleen Gorden
PHOENIX - The 2006 Festival of the West will not only feature a celebration of all things Western from “shoot-outs” to shopping, it will also offer three days where the public can sample authentic Western grub cooked “as it was on the trail.”
(...)
On the Old West cattle drives, the most welcome sound was old “Cooky” (aka"bean master”) slugging away at the chuck wagon’s dinner bell, signaling that the three B’s - beef, beans and biscuits - were about to hit the tin plates.