What's the minimum amount of clothes one needs in the Midwest? Specifically in the State of Illinois?

I'm a male wondering how I could reduce my tacit support of sweat shop labor and unsustainable practices through the purchase of so much sweat shop made clothing. If I wanted to be a (green) minimalist what clothing items should I own that would adequately clothe me in the Illinois Spring, Summer, Fall and Winter? Where's the balance between having a ton of clothes (and needing a ton of storage space, but being able to go some time without washing) and having a small amount of clothes and having to wash often (and wear out the life of the clothing)? If you have experience in downsizing you're wardrobe / living simply and sustainably I'd love to hear from you. If you got some thoughts / ideas I'd also love to hear from you. Citations would also be greatly appreciated! : )