They rapidly got up to liquid nitrogen temperatures so when I was in high school we would go to the welding supply shop, bring back liquid nitrogen to the lab, and do the Meissner effect demo

https://www.youtube.com/watch?v=HRLvVkkq5GE

Liquid nitrogen is very easy to handle (ordinary thermos), liquid helium is much more expensive and harder. WHen I was in grad school the one required class was the Physics 510 lab and for that I did an experiment that involved second sound in superfluid helium and that involved cooling stuff down with liquid nitrogen first, then rolling up a huge dewar full of liquid helium, attaching a vacuum pump to get the temperature down to 2K, etc. For all that trouble you get to see

https://www.youtube.com/watch?v=UNpKCYZFfDU

That said, it was a long time before really good superconducting tape for fusion reactor magnets and stuff like that became available.

133K is the record for them