The birth of the modern mattress, as we know it.
Edwin Bushnell’s concept is often cited as the original innerspring mattress. This patent was just one step in the many improvements that came along in box spring beds, bed bottoms, and mattresses. Though it resembles a modern “open coil” mattress, it was not that developed at that time.
Bushnell’s Innerspring Patent (Box Spring Beds: “Some Box Spring Bed Patents 1869-1871”)