In the United States there are well-known cities or cities that have significant economic weight that are not the capitals of their states, such as New York, Los Angeles, Chicago or Miami. In this country it is unusual for the state capital to be the most important city, something that is common in the rest of the world. There are two main reasons behind this phenomenon, one historical and the other political representation.
Ancient capitals of the United States that lost weight
The first reason is that the capitals were established between the 18th and 19th centuries, when they were more important cities or had some specific relevance. For example, being at the crossing of two navigable rivers or at a railway junction. Over time, other cities overtook them in population or economic weight, but the state capitals did not move. This is what happens in California, whose capital is Sacramento, located further inland. This city had enormous importance during the Golden fever of the 19th century, but over time it languished in favor of Los Angeles, San Francisco or San Diego, on the Pacific coast.
The second important reason has to do with political representation, since the United States is a country that is quite meticulous about that issue. It is a legacy of its independence in times of the Enlightenment and the precepts of the time, from the division of powers to republicanism. Thus, many capitals in the country seek—or once sought—to be accessible from the entire territory they represented and for citizens to take a similar amount of time to reach them. With this they sought to prevent certain areas of the state from feeling abandoned or from giving priority to access to a specific city just because it had greater weight. This is the case of the state of New York, whose capital is not the city of the same name but Albany, located at the most important north-south and east-west intersection in the region.
The case of Washington DC
This logic has even occurred at the national level. During the American War of Independence, the capital was in different cities—where Congress met—from Philadelphia to New York, passing through Boston and Baltimore. However, in its Constitution the intention was clear that the future capital of the country would be located in a special district, outside the jurisdiction of the federated states. This idea took shape between the end of the 18th century and the beginning of the 19th century in the city of Washington DC, officially the District of Columbia, created from scratch for that purpose. The latter would also be done by Brazil (with Brasilia instead of Rio de Janeiro), Australia (Canberra instead of Melbourne), Nigeria (Abuya as a replacement for Lagos) or Pakistan (Islamabad instead of Rawalpindi).
In the case of the United States, Washington DC became the capital for a political reason. In 1770, members of Congress agreed to move the capital, then New York, to a new federal enclave. President George Washington decided where the city of the same name would be: on the banks of the Potomac River, close to other ports to facilitate the transatlantic connection, and closer to both the northern and southern states. It was a compromise in which the Federalists gave up their objective of placing the capital on the Hudson River in exchange for carrying out a financial plan to pay the American debt from the War of Independence, which would end in 1783.