Some characteristic of developed countries are a good economic activity, generally organized government, and a country full of wealth.
The architecture style is different. romanesque churches came first. they were bulky, strong and had really thick walls. their windows were regular roman arched shapes. they usually have lower ceilings and not much light inside.
Gothic cathedrals came later. they have pointed arches, lots of tall windows for light stained glass and flying buttresses to help support the higher and thinner walls.
After civil war the slaves that were released needed jobs so they worked as share copers by keeping up the fields for the owner and they would either be paid or get a certain amount of the crop.
The 13th Amendment abolished slavery