Which preposition to use with illiteracy

of Occurrences 9%

"But what would you say was the first thing needed in the fight against the almost total illiteracy of the freedmen?" "Why, teachers, I suppose," said J.W.

among Occurrences 3%

In all such commonwealths except Arkansas, Louisiana, Florida, and Mississippi there was an increase in illiteracy among the free blacks.

in Occurrences 1%

The Senator from New Hampshire, who is so conspicuous in this movement, appalled the country some months since by his ghastly array of illiteracy in the Southern States.

Which preposition to use with  illiteracy