(Quick aside: I always thought that a Bowie Knife and an Arkansas Toothpick were the same thing, but it turns out they're slightly different styles of hunting-and-fighting knives... which were both originally made by the same knifemaker in Arkansas. Huh.)
The movie opens with Jim Bowie (Alan Ladd) leaving his Louisiana backwoods home for the first time to go sell his family's lumber in New Orleans. In New Orleans, he gets tangled up with the aristocratic de Bornay siblings, Narcisse (Douglas Dick) and Judalon (Virginia Mayo). He quickly falls for the spoiled and scheming Judalon; Narcisse tries to warn his new friend away from his sister, but of course, Jim Bowie's not thinking with his head at the moment.
Nothing Jim Bowie does convinces Judalon he's worthy of her love. She doesn't dig poor guys. Oh, she enjoys kissing him from time to time, and flirting with him, but no, she could never love a poor man. So, Jim goes home, works hard, and gets rich. When he encounters Judalon again, he's on an equal economic footing with her... and she's married. But Judalon claims she's trying to get a divorce. Jim believes her, of course.
And then there's this whole thing involving horse races where Jim enters a horse race, and his horse wins, and all the aristocrats refuse to pay their gambling losses unless he can prove he owns the horse. Insults and challenges ensue, and Jim ends up attending a duel as the second for a friend. The duel is a set-up, an ambush to kill both Jim and his friend because they just don't belong in the fancy New Orleans world, no matter how rich they get.
The movie does a reasonably good job recreating the Vidalia Sandbar Fight here -- a real-life event where a duel turned into a brawl. Jim Bowie gets shot, then stabbed with a sword, but cuts down his opponent with a special knife he had made to his specifications. Oh, and he still has the other guy's sword sticking out of him when he does it (which is historically accurate).
Judalon reneges on her promise to leave her husband for Jim Bowie. He leaves for Texas, hoping to find a new purpose for his life. But he's ambushed on the way and left lying on the road, presumed dead. There, he's found by Senorita Ursula de Varamendi (Phyllis Kirk), who takes him to her family's home so he can recover.
It turns out Ursula's father is the Governor of Texas. She clearly would like to get together with Jim Bowie, but he is still obsessed with Judalon. He leaves Texas, saying he's going to wrap up his business affairs in New Orleans, but Ursula can see it's really so he can have one final chance to find and woo Judalon.
Bowie encounters Judalon and her husband Phillipe (Alf Kjellin) on a riverboat. Phillipe is a terrible gambler and desperate for money. When he loses a huge sum of money to some card sharps, Jim saves the day by exposing the cheaters and getting Phillipe's money back. Judalon tells her husband she's leaving him for Jim. Phillipe decides to ambush Jim in his cabin on the boat. There's another guy called Black Jack Sturdevant (Anthony Caruso) aboard the boat and planning to kill Jim too because of reasons. (I kind of left out his whole part of the plot, but he's been after Jim Bowie for a while now -- and he stole Jim's knife.)
While the main plot of this whole movie is made up (everything involving Judalon, basically), it does at least hit some facts here and there. It's one of those "well, this COULD have happened" sorts of movies. And it's a good time -- lots of knife fights and duels and brawls, Alan Ladd looks gorgeous throughout, and he even gets to do some stunts. The two things that you would think most likely to stretch your credulity -- that fight where he kills a guy while he's got a sword is sticking out of his chest, and the fact that he married the governor of Texas's daughter -- are totally true.
Is this movie family friendly? Basically. There's a lot of hand-to-hand violence and some gunplay, but it's all very '50s-style and non-gory, non-scary stuff. Judalon clearly is untrue to her husband, and even kisses Jim after she's married to Phillipe, but it's very tastefully handled and could even be a good talking point for parents and children about what marital infidelity is.
You can easily find The Iron Mistress on DVD, but I don't know that it's streaming anywhere.