From a MTA email:

REMINDER: Wednesday-Before-Thanksgiving MARC Schedule

In anticipation of early departures on Wednesday, November 26, 2008, for the Thanksgiving Holiday, MARC will operate amended services on each line. Please scroll down to view each line.

PENN LINE

There will be an extra train departing Washington at 2:50 PM, making ALL stops to Baltimore.

Washington DP 2:50 PM
New Carrollton 3:01 PM
Seabrook 3:05 PM
Bowie State 3:12 PM
Odenton 3:19 PM
BWI Marshall 3:26 PM
Halethorpe 3:33 PM
W. Baltimore 3:38 PM
Baltimore AR 3:50 PM

CAMDEN LINE

Train 852 will be canceled. There will be an extra train departing Washington at 2:00 PM, making all stops to Camden.

Washington DP 2:00 PM
Riverdale 2:10 PM
College Park 2:13 PM
Greenbelt 2:17 PM
Muirkirk 2:23 PM
Laurel 2:30 PM
Savage 2:38 PM
Dorsey 2:45 PM
St. Denis 2:52 PM
Camden AR 3:18 PM

BRUNSWICK LINE

Train 877 will be canceled and will instead operate EARLY, departing Washington at 3:05 PM. This train will make alll of 877’s normal stops to Brunswick and West Virginia.

Washington DP 2:40 PM
Silver Spring 2:54 PM
Rockville 3:06 PM
Point of Rocks L 3:34 PM
Brunswick 3:50 PM
Harpers Ferry, MD 4:01 PM
Duffield’s, WVa 4:14 PM
Martinsburg, WVa 4:35 PM