Anyone who has spent any amount of time studying the 19th century is aware of colonization efforts that existed early on. Lincoln supported voluntary colonization, as did Madison, Monroe, Clay, Breckenridge, Robert Lee, and many others. Why is it such a surprise to you?
I didn't say it was a surprise; I wrote that it was not talked about too much in my school's history classes.
It has been awhile; I don't remember for sure if the teachers even brought up the subject. One of the students may have brought it up.
This was during the early days of the federal takeover of local public schools so I'm not sure what was, or was not, permitted to be said by Washington D.C. authorities.