Thanks, circus. Your link doesn't work (the pdf only appears in a frame on the site itself), but I've been reading around on his site quite a bit. The muntin profile is correct for the period, but I just have to wonder about those large single bottom panes.

For anyone else who wants to read the pdf, if you go here and scroll way down the page, there's a link "These topics discussed here by James Garvin" that opens the frame.

The most important factor would be the architectural style of the house.

9 over 1 double-hungs were common in Colonial Revival houses roughly from 1880 to 1950 and in Neo-Classical houses after 1895.

Thanks for the dates, Renovatr8. The historians who surveyed the neighborhood back in the late 1980s evidently hummed and hawed and then shrugged and gave up and called it "Florida Victorian Vernacular."

9/1 or 6/1 (even 12/1) very much a thing of the revivals of the teens through WWII.
Casey

The Colonial Revival style came into vogue around USA's centennial -- 1876. So that's the earliest but your windows could be much, much later. People renovating their homes is not a new phenom -- an 1870's house can easily have windows that the homeowners considered upgrades dating from 1900, 1920, 1950, whatever.

Thanks, Casey and tomtuxman.

>People renovating their homes is not a new phenom -- an 1870's house can easily have windows that the homeowners considered upgrades dating from 1900, 1920, 1950, whatever.

For sure, but it really puzzles me why they didn't put one of the fancy new windows in the most prominent spot. Oh well, I was in another local house that's run as a museum now and the curator said to me, "This house is 90% blindingly obvious and 10% a complete mystery," and I suppose that's true of most old houses.