Perhaps the biggest upside to the globalized economy is how easy it is to get just about anything we want or need. Perhaps the biggest downside, aside from the carbon emissions created from transporting everything across the globe, is that we almost never know where these things have come from or how they were produced.
Sweatshop-made clothing is no secret, but beyond vaguely knowing they exist, it's hard to pinpoint whether the clothes we buy were made in a sweatshop, and it's even harder to learn how to shop for clothes that you can be confident were not made in a sweatshop.
The long hours, the poor wages (pennies an hour), the practice of chaining workers to their workstations and their lack of freedom even to use the bathroom—not to mention the repetitive motion injuries caused by endless hours of tedious labor (think the finger-equivalent of carpal tunnel in computer-users)—are a few reasons why sweatshops should not be the system of production in a world we call modern.
A few pointers
Don't fall for the "Made in the U.S.A." cover.
There are plenty of sweatshops on U.S. soil, but this label also often implies production in U.S. territories that are conveniently exempted from U.S. labor laws, or even that just the finishing touches were applied in the U.S. (i.e. buttons), when the rest of the garment was made overseas.
Look for union-made instead.
The Union House and UNITE union labels are reliable ones. Also check out resources like Sweatfree.org and see if anyone in your city or state is already working against sweatshops, and join the fight.
Look for brands boasting a fair trade-certified label.
Though not all third-party certification processes are reliable, the international fair trade organizations are. (The Fair Trade Labeling Organization, Fair Trade Federation, Global Exchange, the FairTrade Foundation, and TransFair USA are all great resources for learning more about fair trade and for connecting with companies and products.) World of Good and its Fair Wage Guide are also worth mentioning.
Look for companies that wear their ethical standards on their sleeves.
Green America is a great place to start.
Buy used or recycled.
The most environmentally responsible and a surefire way to shop sweatshop-free is to buy already-used goods. You'll not only reduce pressure on resources and cut down on the emissions from transporting goods from factory to your shopping cart, but you're also likely to support an independent retailer in your community.
All the benefits of reduced consumption from the previous point, times ten.