Making T-Shirts

What is the simplest, least exploitative way to have a few t-shirts with a simple slogan made?

Ideally through a US-centered company.

I'm not looking to include crazy designs or colors, just a black text slogan on a white shirt.

i had good results with an online company called customink

If it's only a few, you might consider getting some blank shirts from a thrift store (there are always a few that are unworn) and do an iron-on transfer (or make a screen if you're handy with that sort of thing).
If it's a simple slogan, you could make a stencil and draw it out with fabric markers.

Revive
I’d like to have a couple of shirts made with a simple graphic. Any recommendations?

Zazzle is the easiest though not necessarily the cheapest, depending on where you live. Though I did make this shirt design which they refused to sell because they are cowardly shits, even though it's clearly a fair use parody.
https://pbs.twimg.com/media/FLRHPsUVgAcIvbQ?format=jpg&name=medium

argh, big pic, sorry

Thanks