Why does the Southern United States have alot of woody areas even in urban cities?

The southeastern part of the states gets moisture from the Gulf of Mexico from wind currents that carry it north across the states. The rest of the country depends on air currents from the Atlantic and Pacific oceans for their rainfalls. I live in North East Texas with lots of wooded areas and 90% of our winds come from the south and off the Gulf. We get app. 50 inches of rain every year. The farther west of here it gradually gets dryer until you get to West Texas away from the gulf area and there the average rain fall is 9 inches per year.

 In reality, there are more trees in the U.S. today then when the pilgrims came over because of re-planting and forest management.

Climate is one reason.  Another reason is city planning.  Cities can and do plan to keep wooded areas for parks, etc., for citizens and visitors to enjoy.  However, not all cities have the same climate or natural resources.

Climate Conditions

I say let it grow. You might live in Thneedville.

Humans like trees so plant them even if they do not grow on their own, and if they grow on their own, the humans let them?

The trees really like that climate and soil conditions, so will grow if allowed.  We humans could destroy them, but it is a lot of work, and really, not anything most of us actually want to happen.  Trees are good.  Shade from trees is nice on a hot sunny summer day.

Because of the climate and soil. Notice they have few cactus yet cities in the desert have lots of cactus and very few trees.

Because they can.

The cities grew up before all the trees were cut down.  So they were able to keep them.

That doesn't mean they're southern, it means they're relatively young.

Cuz we like f@cking trees, that's why.

You should try it..I think your brain could use some oxygenation.

Because they love to play with woodies, I guess...