Caspar Crouch, a member of the pure-blood Crouch family, married Charis Black c. 1940. They had one son and two daughters.
Caspar Crouch may be the father of Barty Crouch Sr. -- the dates seem to make sense and the Black Family Tree notes that Caspar and Charis had one son as well as two daughters. The dates for Caspar are deduced from the dates given for his wife: 1919-1973. Assuming Caspar was of similar age, we assume that they married around 1940-1945. All this is reasonable guesswork, of course.