Mike, did you get any other wood from that tree? If you got some, try to split it. That will tell you in a hurry if it's sweet gum or poplar.
Roy G
They were able to split the poplar, but there was also sweetgum and it stopped the splitter cold in it's tracks.
Looks like poplar. Although sweet gum may be a better choice for a anvil table as long as it stays indoors. Ever tried to split a sweet gum log?