Rubicon posed this very interesting question over at RFM.
Here are my thoughts on why so many people came from England, Wales, Scotland and Scandinavia:-
Look at it from their point of view. Many of them were craftsmen. But they were not always paid what they were due. In Britain they lived in small, damp and cold terraced houses, often very close to the factory where they worked. If the womenfolk put the washing out on a washing line strung up in the back yard or over the alley at the back of the houses, the pollution would make it dirtier than before it was washed.
They were fed stories of the rolling pastures of Utah, how you could have as much land as you wanted, how the weather was nice and the air was pure. And would make your child with the chest condition breathe good, wholesome, clean air for the first time in its miserable life.
It is surprising that more did not accompany them.
And when they found out the awful, terrible truth?
Why, there was Sister Snitch and Bother Tittle-Tattle ready to carry tales back and then there was Brother Danite ready to make sure they toed the line!
Well, you wouldn't want to just vanish like that Scandinavian troublemaker who left a wife and three children to starve under the malevolent eye of Brother Brigham, prophet, seer and revelator, would you?
And as luck would have it, Brother Brigham had a close confidant of his marry the beautiful blond woman for himself. Joining his 12 other bitter, resentful older wives.
What's that? She's... You don't think she is officially a widow? Well, hush! If the Lord's anointed has ordained the wedding, then please say it must be so! Don't question it, for pities sake! Least you want to take the walk into the night with the Danite Brethren!
They were not idiots. The were given the hard sell and then were too terrified to be able to do anything about it.