To be honest, honesty has nothing to do with your post, since suffrage was mainly for voting, not emancipation. I'm sure Tubman was a minor historical figure in the Manhattan Project, too. So what? No one considers Tubman "minor" in any way. You're just spewing slander.
And concerning the Underground Railroad to help slaves escape, she was, as I said, a heroine of enormous courage and faith in God. To try and denigrate that heroism through misdirection puts you on the opposite side of humanity from her. So it's no surprise you can't see her historical value to this country and all of humanity.
No doubt history has placed Tubman higher than her accomplishments call for.
If TPTB decided that someone black should be on a US currency note, my vote would have been for George Washington Carver.
Born a slave, he attended Iowa State University and spent his life teaching and researching at the Tuskegee Institute.
His work with peanuts, sweet potatoes and farming methods were designed to help the small farmer.
Or perhaps Booker T Washington.
Another man born into slavery.
He graduated from Hampton Institute and attended Wayland Seminary for a short time.
He became the first leader of the Tuskegee Institute and championed the issues of education and self help among the black communities.
He was a vocal and persistent opponent of northern militant WEB Du’Bois who later helped found the NAACP.
Either of these gentlemen would have been fine additions to the faces gracing our currency.