Final answer:
The most important Mississippian city from 1050 to 1300 was Cahokia, known for its central mound Monk's Mound, significant population, and cultural advancements.
Step-by-step explanation:
The most important city among the Mississippian people and the largest city north of Mexico from 1050 to 1300 was Cahokia. This impressive city, located near present-day St. Louis, was the central hub for political and trading activities along the Mississippi River. At its peak, which was around 1250 CE, Cahokia boasted a population as high as 30,000 people. Its well-known Monk's Mound was the largest of the 120 mounds in the city, resembling a ten-story building and covering 13.8 acres. The top of this mound likely housed a significant structure, possibly a temple or the residence of the ruling chief. Moreover, Cahokia was notable for its large defensive wall, community plazas, and an astronomical observatory wood henge, marking its sophistication and cultural importance among the Mississippian chiefdoms.