The bolt that holds the flag pole unfurling mechanism planted on the moon by the Apollo 11 crew, because it’s likely to be part of human history for quite some time to come.

Also, I’m aware that the moon landing wasn’t in 1959, but I imagine a NASA engineer pulling it out of a bucket of bolts from previous projects, ie. memorable place in history, not particularly noticeable or special.

Disclaimer: I have no knowledge whatsoever of the actual construction of the flagpole or its origins.