As of 1900 (interpreted from Form CT1000), the Pennsylvania Railroad -- which did not include "Lines West of Pittsburgh" -- was organized into Grand Divisions, Divisions, and Railroads. Railroads represented in bold are included in the listings but are believed to be independent railroads (many are confirmed so).

 

Grand Division Division Railroad
United Railroads of New Jersey Division     New York Division  
Central R.R. of New Jersey
New York & Long Branch R.R.
Amboy Division  
Belvidere Division  Belvidere Delaware R.R.
West Jersey Railroad
Camden & Atlantic Railroad
West Jersey & Seashore R.R. Cape May Division  
Atlantic City Division  
Pennsylvania Railroad Division Philadelphia Division Schuylkill River Branch
Delawre Extension
Junction R.R.
 
Skuylkill Division  
Frederick Division Colombia & Port Deposit R.W.
 
Middle Division  
Lewistown Division Sunbury & Lewistown R.W.
Milroy Branch  S. & L. R.W.
Kishacoquillas Valley R.R.
Huntingdon & Broad Top Mountain R.R.
Bedford Division Bedford & Bridgeport R.R.
Tyrone Division Lewisburg & Tyrone R.R.
Tyrone Branch
Bald Eagle Valley R.R.
Tyrone & Clearfield R.W.
Altoona Division Altoona Yard
 
Pittsburgh Division  
Cambria & Clearfield Division  
Cresson & Irvona R.R.
West Pennsylvania Division Indiana Branch
West Pennsylvania R.R.
Monongahela Division P. V. & C. R.W.
Philadelphia, Wilmington & Baltimore R.R. Maryland Division Washington Avenue
 
Baltimore & Potomac R.R.
Washington Southern R.W.
Central Division  
Delaware Division  Delaware R.R.
Baltimore & Delaware Bay R.R.
Northern Central Railway Baltimore Division  
Susquehanna Division  
Shamokin Division Shamokin Valley & Pottsville R.R.
Sunbury Division Sunbury, Hazleton & Wilkes-Barre R.W.
Elmira Division E. & W. R.R.
Erie Railroad
Canandaigua Division E. & L. O. R.R.
E. & L. O. R.R. Sodus Bay Branch
Philadelphia & Erie R.R. Division Sunbury Division North and West Branch R.W.
 
Eastern Division  
Middle Division  
Western Division