Short answers, pulled from the story.
The House of Burgesses divided Virginia into four incorporations in 1617 before establishing eight shires or counties by 1634. These early units included James City, Henrico, Charles City, and Warrosquyoake.
Louisiana adopted local divisions called parishes that dated back to both Spanish colonial and French colonial periods. New Orleans serves as a consolidated city-parish today.
Los Angeles County California held 10,014,009 residents in 2020 making it more populous than forty-one individual states. This number slightly trails the combined total of the ten least populous states plus Washington D.C.
Fourty-one independent cities exist across the United States where no county nominally exists. Baltimore, Maryland; Carson City, Nevada; and St. Louis, Missouri are examples of such cities.
Connecticut abolished county governments in 1960 leaving eight counties as mere legal entities. Regional councils of governments now handle some functions like infrastructure planning and emergency preparedness.