I love it that someone besides me is interested in historical height questions! Your average height of army recruits doesn't reflect the fact that there was a vast discrepancy between the wealthy and poor recruits, due to nutritional differences. At this period the difference between upper- and lower-class males reached 22 cm. by age 16, the highest in all of Europe. The English poor were shorter than German servants, whereas the wealthy boys were only about 2.5 cm. shorter than today's U.S. standards. It was true that you could tell just by looking who was in the "gentleman" class and who wasn't!
I grew up in Hawaii and remember visiting the missionary museum; the beds and clothes were extraordinarily tiny. I had Japanese aunts, born in the 1930s, who were under 5 feet tall, but they could never have fit into those dresses! It is possible that the size difference between men and women was somewhat greater than now; in the mid-18th century, future president George Washington (6'2'') married Martha Custis (5').
That's all I know on the subject, although I am sure there are others out there who could tell you a lot more than I could. I have always assumed, however, that Darcy was likely over six feet tall.
