I have looked through the text of the Topeka Constitution and have been unable to locate any such provision. Here’s the only use of the word “negro” in the text. The words “black” and “colored” are not found.
“Sec. 21. No indenture of any negro or mulatto, made and executed out of the bounds of the State, shall be valid within the State.”
Here’s a link to the text:
If you can find the provision to which you refer, I’d like to see it.
It is also fair to point out that this anti-black attitude was most definitely not Old John Brown’s POV.
The competing pro-slavery constitution had this lovely clause:
“23. Free negroes shall not be permitted to live in this State under any circumstances.”
If you can find the provision to which you refer,
Is it not the same provision referred to by the link you just provided?
"The Topeka Constitution prohibited slavery but excluded free blacks from the state."http://www.kshs.org/research/collections/documents/online/topekaconstitution.htm#article15