Nicholas With Stroller, 1957

These are (or were anyway) called pushchairs in England.
When we emigrated in 1964 it seemed like almost all baby things in America had different names. (nappies, prams, push chairs, dummys, cots, carry cots = diapers, baby carriages, strollers, pacifiers, cribs, porta-cribs - for example.)
There were no such thing in Connecticut as the "reins" Nicholas is wearing. People were horrified by the idea!