Mark Twain made the trip. So did P. T. Barnum. They, along with a slew of 19th century European travelers, could not resist the draw of Salt Lake City, Utah. The attraction? The Mormons and their many wives.

But as Penn Professor of Law Sarah Gordon shows in her book, “The Mormon Question” (North Carolina, 2002), the Mormons’ practice of polygamy did more than just spark curiosity, jokes and gossip; it left a legacy in constitutional law and political theory that still governs religious life in America.

In 1852 Brigham Young, then leader of the Church of Jesus Christ of Latter-day Saints, popularly called the Mormon Church, publicly announced the faith’s sanction of polygamy. What followed “were intense debates about whether or not the federal government would have the right to open the bedroom door and interfere in the relations of husbands and wives,” said Gordon.

Anti-polygamists saw the practice as an analog to slavery, believing, Gordon said, “that women were bullied into it and frequently kept there through violence or other forms of coercion.” Ann Eliza Webb Young, one of Young’s runaway wives, testified to as much. In the 1870s, she traveled the country, visiting congressional courtrooms to lecture about the miserable and disastrous life she shared with Young.

But beyond the concern for Mormon wives there were other worries as well. “[Opponents feared that] polygamy would produce a tyrannical set of men who were tyrants at home and thus wouldn’t know how to behave as respectable, productive citizens in a democracy that demanded equal treatment of all,” said Gordon. Mormons, they felt, were bent on conquering the country and betraying its true interests.

Yet for every protest against polygamy, Mormons had a counter argument. Polygamy was a divine command, they said. “[It] was the ticket to greater exultation in the after life. This was the most pure and most righteous of all family structures,” explained Gordon. They wondered how polygamy could be unnatural and inhumane when so many other societies practiced it. More importantly, they claimed protection through the constitutional principles of religious freedom and local self-government.

And even though Mormons made up only a small percentage of the population, the debates continued, surfacing in the pages of dime novels, newspaper cartoons and the Congressional Record.

“They were extremely ambitious and their rhetoric was often combative,” said Gordon. “But were they a threat to the rest of the country? Probably not really.”

Still, quiet wasn’t had until 1878, when the Supreme Court handed down its decision.

“The Mormons lost flat,” said Gordon. “What had looked like a dangerously independent political entity to those outside the faith now looked unconstitutional and even treasonous.”

But Gordon said polygamy

wasn’t the real issue. At stake was whether Americans, then and now, are free both to believe in and to act on what they believe. “The really big issue was whether a given part of the United States had the right to structure its laws differently according to religious principles,” she said. “I think the answer to that would still be a resounding no.”