There is a brief history here on this Wiki page: http://en.wikipedia.org/wiki/St._Louis_–_San_Francisco_Railway The St. Louis San Francisco was merged into the Burlington Northern, not the Missouri Pacific.
The BN acquired the Frisco 11/21/1980. I lived in St. Louis at the time and everyone had to call the Frisco offices to hear them answer the phone “Burlington Northern Railroad”.
Yes, but…
Sometime in the 1920’s or 1930’s the MP acquired parts of the Frisco. For example, the MP in DeQuincy LA is ex-Frisco.
The Frisco wasn’t “absorbed” but some assets changed hands.
When I read the history of the Frisco I thought, “man there is one railroad that doesn’t deserve to exist”. I had never read about so much mismanagement, poor decisions, bankruptcies, etc. I had to have read that book almost 25 years ago, but off the top of my head I recall they were also owned by the Santa Fe at one time and were partners in the Atlantic & Pacific fiasco. That is why there is so much parallel ATSF & SLSF track in Kansas.