Too many people even today still don't realize the "B" designation merely meant lower budget -- or, sometimes, low budget.
This particular "B" movie -- the first in a series -- didn't cost as much to make as, say, an equally action-packed flick with Errol Flynn, but there is still an entertaining aspect.
The cast is a good one, with some top-notch talent not even getting screen credit. Such stellar names as John Hamilton, and Eddy Chandler and Lane Chandler, Pierre Watkin and Pat O'Malley, are not names at all, until a fan comes to IMDb to look.
Ronald Reagan is the star, and he was still looking to break out of the ranks, after being overshadowed (and I honestly don't understand why, after seeing the film recently) in "Brother Rat" by Eddie Albert.
Yes, Albert turned into a great actor, but in "Brother Rat" he was rather blah, possibly because his character was, and Reagan came across stronger, again possibly because of his character.
In this movie, Reagan shines: He is a very good-looking man, with a great smile, and he handles the action scenes well, and, perhaps most important, he displays a very winning personality.
The Brass Bancroft character appeared in several more films of this popular series and finally, after doing well as secondary characters in bigger-budget movies (with the like of Bette Davis and Humphrey Bogart), he got his chance at stardom.
This "Secret Service" entry might not seem like anything startlingly new today, but in 1939 it broke some ground. Right at the beginning, when the pilot fears being caught carrying illegal aliens, the horrific act surely shocked audiences.
I've been wanting for years to see the Bancroft series or at least a Bancroft movie, and finally, thanks to Turner Classic Movies, I have.
All in all, it's a good story with a million-dollar cast.