Ancient Sumer, in Mesopotamia, began around 5500 to 4000 BC and it developed from a settlement of West Asian people, according to archeological findings. Sumer passed through several stages and became known as one of the first and most important civilizations. However, history shows that the period during which Sumer developed mostly as a civilized state was during the Uruk period in the 4th millenium BC. What made them different from the earlier human settlements is first, that Sumer was one of the first civilizations to have an established language that changed and evolved through time with the contact with other civilizations, such as Akkadia. In fact, they developed a series of pictograms that were recorded in disks and that served for record keeping. They also organized into cities. In fact, Summer counted with more than 20 established cities, organized as city-states. These city-states were settled with houses around a temple dedicated to a god or goddess and each were led first by priests and then by kings. They also were the first to use slave labor for agricultural and crafting purposes. Sumerians also began trading with other lands and their population grew greatly during the periods. Another important thing was that, aside from the priest or king who led each city-state, Sumerians did not have rankings as such and men and women shared the same respect and level of importance. Sumerians were also known for their pottery and most of it depicts the way of life in this civilization from its beginnings to its end.
In the case of Egypt, it started as a nation in 3100 BC, after a unification of the divided kingdoms of the prehistoric Egypt under the rule of Menes. Egypt reached the pinnacle as a civilization and power during a period called New Kingdom and then it declined until in the year 30 BC, Egypt fell into Roman control and became a province. Because of their ability to adapt to the conditions in the Nile Valley, where Egypt formed, Egyptians created a civilization that was very strong agriculturally, culturally and politically speaking. They formed their own writing system based on pictograms and hieroglyphs and they began a system of collective construction systems that characterized them through the centuries. They also had a central government, led by the pharaoh and unlike other civilizations, women and men shared almost equal rights, women being able to even inherit land. Egypt also characterized for its pottery and mostly its sculpture, which became and is still famous. Unlike other nations, Egypt did have social strata, with the king being at the head, followed by the priests and then the military leaders, then laborers and slaves. They also were organized into cities, much like Sumerians but the development of their architecture was better. Egyptians produced art to serve a specific purpose and not just for beauty. As far as literary works, it is important to know that Egyptians first began to use writing to inscribe tombs and evolved from there and during the Old Kingdom, writing started to be inscribed in papyrus, which was the paper of the day.
Finally the United States developed as a civilization first when the first Paleo-Indians, thought to have migrated from Siberia reached mainland 12000 years before. The United States counts with a spoken and written language called English, does not have a centralized government but Federal, enjoys the freedom of religion, does not have castes or social strata like any other countries and it never did, based on the principles it was founded on. From its beginnings the US also enjoyed the contact with culture and its architecture was inherited from the styles established in Britain and other parts of Europe, given the immigration that settled there. As for art, it is very varied and well developed in all its forms. In literary terms, the United States has also enjoyed the presence of great writers and poets who have created some of the best known stories and poems in the world.