You could say that, but you shouldn't be surprised if people think you're an idiot for thinking it and saying it.
No "minority"- not Irish, not the Chinese, not the Indians, not the Mexicans- were treated "almost as bad" as people of African descent. I'm not saying that those people weren't maligned and treated as sub-humans... they were. But, not "as bad" as African descent people. If you were any of those others, you weren't considered property, codified by law, based on your ethnicity. You weren't held in high regard by European whites, if you were a Red Man. The Red Man were at least allowed to put up a fight, and that actually gained them some respect. Blacks were subjugated in every way imaginable. It's not even close.