In Walmart for $11 you can buy 1 pound of chicken breast ($2/lb), 1 pound of rice ($.50/lb), 1 pound of tomato sauce ($.50), 1 pound of carrots ($1/lb), 1 pound of bread ($.88/20 oz), half pound of butter ($3/lb), half pound of cheese ($2/8 oz), and still have $4 left after tax. You can literally feed a family of four with this. Of course, most nominally poor people will spend much more, because they're not actually all that short on money.

If you take 1860s unskilled worker wage and spend it all on food, you'll get about as much as you could with SNAP benefits (~$130/month) today. The UBI is already here, it's just our standards have rose significantly.