In the early years, 1700's making hay was one of the most dreaded farm chores. It had to be hand-cut with a sickle or scythe and hand-raked with a wooden rake or fork. On a good day, a farmer could harvest 1 acre of hay.
Mechanical revolution. In 1840, seeding tools improved and the steel-toothed dump rake was invented.
How many acres of hay can one person rake in one day, today?