Following World War I, baby carriages were updated to include safety features that remain in today's prams, like larger wheels, footbrakes, deeper and roomier prams (which made it harder for kids to escape), and lower, sturdier frames (so if little ones did manage to climb out, it wasn't far to the ground).
In 1889, William H. Richardson patented a more functional baby reversible carriage — meaning the bassinet could be positioned to face both out and in. In addition to modernizing the carriage, Richardson made structural changes that allowed for the wheels to move separately (until then carriages had axels connecting the wheels, preventing independent wheel movement), making the stroller more maneuverable and convenient for parents.
"" is short for "perambulator," which is essentially a stroller for a baby. People in the UK may refer to the stroller as either a pram or a baby carriage. These first became popular during the Victorian Era, and the typical carriage was black with high wheels, with a bed for the baby to lie in and a half cover that could be used to protect the baby from overexposure to the sun.