In 1979, when anthropometric history was still in its infancy, Robert Fogel and collaborators reported that the height … were offered, not until 1987 was the comprehensive solution to the puzzle offered that the height decline was due primarily …

proportion of shorter men to volunteer for military service thereby driving down the mean height of soldiers even if the height … declined. A thorough analysis of the Union Army height data, considering recruiting periods as short as 90 days during which … height of soldiers beginning with the birth cohorts of the early 1830s is representative of the trend in the physical stature …