What is wrong with my tomatoes? I can't tell if it is BLIGHT or WILT. What is the difference?

It really doesn't matter which of the two it is because they are both fungal infections and are treated the same way. It might also be "leaf spot" disease(look that one up too). I live in Minnesota, and battle the same thing and I can tell you it is a very hard battle to win! I swear the darn spores blow in the wind from distant locations to kill my tomatoes every year. But, here are some things you can try...NEVER plant your tomatoes in a location that has had this problem the previous year. It can overwinter in the soil and get splashed up onto your plants year to year. Use a mulch around your plants, either plastic, wood chips, anything to put a barrier between your plants and the soil. NEVER water the plants overhead, use drip hose or water only at the base of the plant...the disease spreads rapidly on moist leaves. Use a fungicide spray and start using it BEFORE you even see a problem and use it every week throughout the season. This is my least favorite solution because I am allergic to fungicides, so don't do it. If you see diseased leaves, remove them. Grow them in cages or up some type of support: anything to get them off the ground. But like I said, one good rain and a little heat and this disease goes crazy overnight...so good luck! If you can handle using fungicides, they are probably your best bet.