Technically, the states have only prevented dissolution for a bit less than 151 years. The previous streak lasted about 79 years.
Surely, the Confederate secession qualifies as a dissolution.
I am of the opinion that the U.S. would fare better with more states, rather than fewer. If Los Angeles, New York City, Chicago, San Francisco, Dallas, Houston, Miami, Philadelphia, Boston, and San Diego all became city-states, the usual civic corruption would have less impact on the statewide governments of the donor states.
Surely, the Confederate secession qualifies as a dissolution.
I am of the opinion that the U.S. would fare better with more states, rather than fewer. If Los Angeles, New York City, Chicago, San Francisco, Dallas, Houston, Miami, Philadelphia, Boston, and San Diego all became city-states, the usual civic corruption would have less impact on the statewide governments of the donor states.