Like when?
Let's take the sociological example you provided on another post: The Civil War's ensuing years...mid 1860s onto the rest of the 19th century.
Here, we lost more men in that war than ALL other American wars put together.
You would think that of all the sociological reasons that could undergird polygamy, this would be it, right?
But did America -- aside from Mormons -- rush into polygamy in the mid-1860s through the 1890s?
Nope!
Why not?
#1 Recognize that a LOT of the men who died in the Civil War (not sure of %) -- were single or already divorced. In fact, a LOT of teens -- including 15, 16 and 17 yo -- were among the "men."
#2 Sheer sociological replacement of "marriageable men": The males born in the 1840s, 1850s, and 1860s -- of whom there was no shortage -- became of marriageable age in the 1860s, 1870s, and 1880s!
But what about widows in their upper 20s and beyond, you say? What about them?
Some remarried simply because 19th century medicine being what it was, things that could be readily cured -- or readily dealt with -- like even childbirth -- resulted in many women dying young. These men would take a second wife.
#3 The grassroots American culture was dead-set vs. polygamy!
How do we know this?
When Utah became a state in the mid-1890s, it elected as one of their initial congressman a Democrat by the name of B.H. Roberts.
America found out that Roberts was a polygamist. Was especially infuriated America is that Roberts, who became a General Authority in the Lds church, assumed his third wife around 1893 or 94...several years after the so-called "Manifesto" that was meant to ditch polygamy. How could Mormonism, which secretly solemnized at least 260 or so additional plural marriages 'tween the years of 1890-1910, be so publicly two-faced?
Well, that's been the nature of deceptive Mormon leaders from the get-go!
Well, what was the reaction to Roberts being elected in the pre-media days of 1898 America?
America's grassroots, which was committed to upholding the Republican roots of ridding itself of the "twin relics of barbarism" (slavery and polygamy)...the GOP's rally cry of 1856...put together 28 banners that included 7 million signatures. These 28 banners were delivered to Congress in 1898...asking Congress to NOT seat B.H. Roberts as the Congressman from Utah.
Sure enough, Congress sent Roberts back home!
You would think that the culture that saw so many widows from the 1860s, 1870s, 1880s and 1890s might be more sympathetic to polygamy, right? Wrong!
America continued to be a nation of immigrants late in the 19th century. (And more male immigrants made the initial trip than entire families or married men).
IOW, such shortages were made up by male immigrants! In many ethnic sub-groups (blacks, others) there was no shortage of marriageable males...for blacks that was true all along, for others by the 1870s and 1880s, the shortage had largely corrected itself!