I’m used to associating this phrase with Winston Churchill, circa 1909. But here’s an 1891 reference:

There is one great monopoly, and that monopoly is the mother of all other monopolies! You know what I will say! You know that I will say that its name is

PRIVATE OWNERSHIP OF LAND.

It comes in Henry Chase’s book, Letters to Farmer’s Sons.

I realize that to one who stumbles onto this post, this will seem like a radical statement, perhaps appearing to be diametrically opposed to a strongly-held ideal. If so, and you’re willing to explore the topic a bit, you might check out a page over at wealthandwant.com which makes some distinctions