Complex sentence: A loophole allowed the wives of men already in the country to join their husbands, and so the practice of women marrying by proxy and immigrating to the U.S. resulted in a large increase of "picture brides" and, soon after, children.
Split into simpler sentences: A loophole allowed the wives of men already in the country to join their husbands. The practice of women marrying by proxy and immigrating to the U.S. resulted in a large increase of "picture brides" and, soon after, children.