where did greenwood come from?

So I found a Greenwood W. Garrison that enlisted in the 4th Iowa infantry at 46. He, his son-in-law and 4 nephews died in the war.

Enlisted as a Private on 4 July 1861 at the age of 46.
Mortally wounded 22 Feb 1863 at the Battle of Vicksburg, MS
His son John, a son-inlaw and 4 nephews also died in the Civil War

I suspect this name is somehow important to the Garrison family, but why? It's not like Miles was named after him because he died in the war, AFTER miles g.g. had been born.

I also found someone who went to TX named Garrison Greenwood--a minister, I think. There party saw some death to Native Americans. There is also a Prof named that at some school in OR, an engineering school, present-day. Hm.