[tolciho]

control+u for line-kill is probably a recent thing, a random PDF of "The Unix Programming Environment" (Kernighan & Pike, 1984, p.6) has @ as the line-kill character (and # is erase which these days may or may not be control+? (linux often does something wrong with the delete key, unlike the *BSD)).

[kps]

TOPS-20 used ^U. (That's where BSD got it, along with ^W, whence it percolated into other *nix.)

[WalterBright]

I was right. It was the ^U! Thank you.