After Mexico City fell to American forces, president Santa Anna fled the country, fearing retaliations from either American or Mexican forces alike, as it was suspected he played both sides during the conflict for personal gain (he did). Also, many wealthy people, including those in the congress, left Mexico City for fear of their lives.
Without a clear leadership, the Mexican government fell in disarray, prompting those who were left behind to sign the Guadalupe Hidalgo Treaty, to prevent the full takeover of Mexico.
At the fall of Mexico City (Sep 15, 1847), the Mexican government fell as well. It marked the end of the Mexican-American War.
The fall of Mexico City was at the hands of General Winfield Scott.
Tacuba - Mexico City - ended in 1928.
Mexico City
In Mexico, the month of September is the equivalent to our spring time, since in North America, we would be experiencing the end of summer, and the beginning of fall.
The US marching in to Mexico City.
It did. The capture of Mexico City put an end to the Mexican-American War (1846-1848) and forced the Mexican Cession upon Mexico.
Spain qualifies as such. It controlled Mexico from 1521 at the Fall of Tenochtitlan, until 1821 when the Three Guarantees Army (Mexican pro-secessionist forces) entered Mexico City and put an end to the Mexican War of Independence (1810-1821).
US Forces occupied Mexico City.
It was over.
The occupation of Mexico City on December, 1848.
The fall of the Russian fortress that brought the Crimean War to an end occurred in Sevastopol, located in Crimea.