How parents ferry their multiples, from the baby boom to today.

Thefirst stroller for single infants was produced by William Kent in 1753 for the Duke of Devonshire, but it appears that no one thought to expand that model for multiple babies until the late Victorian era. When the two-seater finally appeared, it was only distantly related to what mommies of twins wheel down the street today. Check out this slide show to trace how the double stroller—known at different times as the twin stroller, double carriage, twin pram, and double push-chair—went from being a heavy platform with wheels, available only to the wealthy, to a light, foldable contraption that any parent could take with them on the subway.