Noah Webster
Unconcerned
UNCONCERN'ED, adjective
1. Not concerned; not anxious; feeling no solicitude. He is unconcerned at what has happened. He is unconcerned about or for the future.
Happy mortals, unconcerned for more.
[It has at sometimes before a past event, but about or for is more generally used before a past or future event.]
2. Having no interest in. He is unconcerned in the events of the day.