Short answers, pulled from the story.
Genetic studies estimate the colonization of the Americas dates from between 40,000 and 13,000 years ago. The short chronology theory suggests movement beyond Alaska occurred no earlier than 14,000 or 17,000 years ago. The long chronology theory proposes that the first group entered the hemisphere at a much earlier date possibly 30,000 or 40,000 years ago.
Watson Brake is a large complex of eleven platform mounds constructed beginning in 3400 BCE and added to over 500 years. This site changed earlier assumptions that complex construction arose only after societies had adopted agriculture and become sedentary. It predates the Poverty Point site which was built about 1500 BCE.
The Olmec civilization began around 1600 BCE with the consolidation of power at their capital San Lorenzo Tenochtitlán near the coast in southeast Veracruz. This earliest known Mesoamerican civilization established the cultural blueprint by which all succeeding indigenous civilizations would follow in Mexico. Pre-Olmec civilization began with pottery production in abundance around 2300 BCE in the Grijalva River delta.
Teotihuacan emerged from that vacuum first settled in 300 CE and rose to become the first true metropolis of what is now called North America by 150 CE. The city established a new economic and political order never before seen in Mexico. Its influence stretched across Mexico into Central America founding new dynasties in the Maya cities of Tikal Copan and Kaminaljuyú.
Studies suggest that the Marajoara civilization housed around 100,000 inhabitants during its flourishing period between 800 and 1400 CE. This complex society built mounds and constructed sophisticated settlements while adopting methods of large-scale agriculture through terra preta. The culture existed at the mouth of the Amazon River in northern Brazil.