We aren't sure when they stopped using ropes to hold up mattresses, but they were used at least until the early 1800's.
That is the vintage of the bed in the picture. The earlier beds had holes along the bed rails that the ropes went through, instead of around the pegs.
There is a wooden tool called the bed key - it has a forked bottom. They would insert the tool around the ropes along the sides of the bed and twist to tighten the ropes, re-tying the end of the rope.
It is thought that "sleep tight, don't let the bed bugs bite" comes from tightening the ropes on these style of beds! And they were likely made with hemp rope!
Thanks to Wendy from the Essex Historical Society for providing us with the images and background on this cool hemp rope application!