The Tall Target (1951) review

Having received a tip that a group of men are planning to assassinate Abraham Lincoln, the president-elect of the United States, John Kennedy (Dick Powell), a sergeant for the New York police department, boards a train from NY heading to Washington D.C. with the hope of stopping it, but faces numerous problems on the way there, from having trouble finding a gun, almost getting killed by a hitman and then crossing paths with Colonel Caleb Jeffers (Adolphe Menjou).  It's based (loosely) on the purported "Baltimore Plot" - which was (allegedly) thwarted by detective Allan Pinkerton (portrayed here by James Harrison) - and Mann makes good use of the confined spaces, but Powell is disappointing as the lead (he's not the ideal "tough guy"), the dialogue needed some refinement and too often it strains plausibility (for being so nosy, the passengers seem to "miss" most of the goings-on).  It's interesting that screenwriters George Worthing Yates and Art Cohn put a slave character in this, Rachel (played by Ruby Dee), to remind the viewer what Lincoln was so strongly opposed to and the South was so desperate to cling onto, and unfortunately that animosity still continues to this day: the Republican Party is the Confederacy using another name.