While filming Vertigo (1958), Alfred Hitchcock described some of the plot to its star/frequent collaborator James Stewart, who naturally assumed that Hitchcock meant to cast him in the Roger Thornhill role. This time, the director wanted Cary Grant, who he thought looked younger (though, at 55 y.o. was 4 yrs older than Stewart). By the time Hitchcock realized the misunderstanding, Stewart was so eager to play the lead that rejecting him would’ve caused a great deal of disappointment. Hitchcock decided to delay production until Stewart was already committed to Anatomy of a Murder before officially offering him the North by Northwest role. Stewart had to turn down the offer, allowing Hitchcock to cast Grant.
Now you listen to me, I’m an advertising man, not a red herring. I’ve got a job, a secretary, a mother, two ex-wives and several bartenders that depend upon me, and I don’t intend to disappoint them all by getting myself “slightly” killed. -Roger describes himself
A Madison Ave ad man, Roger Thornhill (Grant), finds himself in the world of spies when he is mistaken for someone named George Kaplan. A British man, Philip Vandamm (James Mason), along w/ his henchman Leonard (Martin Landau) and others try to kill Roger. In a meeting room somewhere, a group of FBI agents (headed by The Professor), are discussing the dilemma of Mr. Kaplan- a decoy, not a real man. Roger investigates, though even his mother is skeptical, and eventually gets framed for murder. He manages to flee the police and runs on board the 20th Century Limited (a train) headed for Chicago. Roger meets a beautiful blond, Eve Kendall (Eva Marie Saint), who decides to hide him in her sleeper berth. He wonders why she’s being so helpful. Vandamm and his men continue to pursue Roger.
The moment I meet an attractive woman, I have to start pretending I have no desire to make love to her. -Roger admits sheepishly
What makes you think you have to conceal it? -Eve asks, matter-of-factly
She might find the idea objectionable. -Roger explains
Then again, she might not. -Eve replies
Though this film is fast-moving and efficiently made, MGM wanted the film cut by 15 mins (to be under 2 hrs). Hitchcock’s contract gave him control over the final cut (which is the most power that can be given to a director). Eva Marie Saint said that Alfred Hitchcock was unhappy with costumes MGM had designed for her, so marched her to Bergdorf Goodman (a department store) and personally picked out clothes for her character. When Landau’s character first sees Grant’s, he comments: “He’s a well-tailored one.” All of Landau’s suits for the film were made by Grant’s personal tailor. The clothes are fabulous (esp. the black and red floral evening dress worn by Eve in Chicago). Grant even has a shirtless scene, proving that clothes don’t only make the man.
 This film has something for everyone within it: a little comedy, a little romance, great snappy dialogue and action…
 There is great acting and a great story. You should be engaged and intrigued, and always surprised and what will occur next.
 Of course the famous crop dusting plane scene and the Mount Rushmore chase are terrific. The former is really more notable for the amount of time taken to build up to the action than the action itself, while the technical work on the latter still looks pretty good.
 Roger Thornhill is one of the best roles Mr. Grant played, during his long career. His chemistry with Eva Marie Saint is perfect.
 Cary Grant’s debonair manner is displayed to the full in this film, even though the peril that his character goes through would cause any normal dude to break into a maddening sweat.
-Excerpts from IMDB reviews