So many and varied were the aspects of farm labor that unmarried farmers were exceedingly rare; to operate a farm household took both a man and woman. And so the word “husband,” originally meaning “farmer,” came to mean “married man.”That statement is a bit timeless in the way it is cast here. When exactly is that transition to be placed?
One way to approach that problem is to see how the word is used in various early Bible editions. In Tynsdale's New Testament from 1525, for example, there are 17 occurrences of "husband" in the sense of spouse (9 times "husband", and 16 times "husbande", with John 4:18 exhibiting both spellings). The NT part of the Wycliff Bible from 1395 spells the word "hosebonde" (30 times) or "hosebondis" (11 times)---which is the earliest English Bible translation that is easily accessible.
Switching to literature then, if we look at Chaucer's Canterbury Tale, for example the Prologue of the Wife of Bath, which probably dates from 1396, we find also:
For, lordynges, sithI twelf yeer was of age \\Similarly, in the metric Chronicle of Robert of Gloucester, which was written between 1260 and 1300, the phrase is also attested (vv.11,300-11,303).
Thonked be God, that is eterne on lyve \\
Housbondes at chirche dore I have had fyve
Euere lokede þis burgeis · wan hii were vorþ idriue ·*Given that we are now back in Middle English, I think the statement as made is misleading; the change in the meaning of the word had happened at least 500 years before the start of the era covered in Howe's book.
Prestles hom was wel wo · þat hii nere issriue ·*
Roberd of caumpedene · þat hosebonde was on ·*
Vor he was a lute clerc · he ssrof hom echon ·*.