So this is what happened....
1836- The Republic of Texas wins its independence from Mexico. Instead of being annexed to the USA, it remains independent. The USA recognizes its independence and supports it, causing tension with Mexico.
1840- The Republic of the Rio Grande declares its independence from Mexico. (POD) The USA recognizes its independence creating more tension with Mexico. Later that year, the Rep. of RG is defeated and annexed back into Mexico.
1845- The Rep. of T is annexed by the USA, claiming lands owned by Mexico, which the USA supports. Tensions continue to grow between the USA and Mexico.
1846- The Republic of California wins its independence from Mexico and is taken over and claimed by the US military. The USA and Mexico go to war in the Mexican-American War.
1848- The USA defeats Mexico and creates the Treaty of Guadalupe Hidalgo, which 1). Ended the war and created peace between the two nations 2). Ceded Alta California & New Mexico to the USA for $18 million 3). Forced Mexico to give up claims to Texas 4). Forced Mexico to recognize the Rep. of the Rio Grande as an independent and sovereign state.
1849- The Rep. of the RG is annexed to the USA due to boundary disputes and debt problems with Texas.
1850- The Compromise of 1850 redrew Texas borders to give RG some of its land claims. In exchange, it was agreed that the rest of the origional Rep. of T borders would be used to create 2 new, smaller, more managible states. With the admittance of Texas, New Mexico, Cristo, and Florida as slave state, the Rio Grande, California, Superior, and Oregon were admitted as free states to balance the power in the Senate. The Oregon Country previously owned by Great Britain is ceded to the USA for unknown reasons.
1854- The Baja Purchase gave the Baja Peninsula owned by Mexico to the USA for $15 million. This was to improve relations and give the USA a longer, more valuable, pacific border. California is ceded the upper portion of the new Baja Territory and the state of Shasta is created from Northern California by the US Senate when they feel that California is to large.
1855- The long proposed Mormon state of Deseret is finally admitted to the Union as a free state. This gives the free states more power in the Senate.
1858- The free state of Minnesota is created from the Minnesota Terr., again without a slave state balance. Tensions rise between free states in the North and West and slave states in the South
I notice you didn't mention the US' ownership of Oregon in the description (perhaps there's another map of yours that does so); how DID we get it?
Oh, and what are you calling the Forsyth Purchase? More US land = always yay in my book.
I know its been a while, but I saw this and wanted to correct myself.
Texas - Everything north of the Rio Grande
Rio Bravo- (1840) Tamaulipas, Nuevo Leon, Coahuila, Nuevo Mexico, Chihuahua, Durango, & Zacatecas (which included Aguascalientes)
Zacatecas - Zacatecas & Aguascalientes
Calfornia - Alta California
Yucatan - Yucatan, Campeche, & Quintana Roo. Occured to annex Tobasco
Tobasco - Tobasco
Baja California- Baja California & Baja California Sur
Sonora - Sonora, Baja California, & Baja California Sur
So if you count all the modern states that rebelled against santa anna it adds up to 17.
Free/Slave State Balance
With Deseret, Shasta, and Oregon creating a free state majority in the senate and led to the American Civil War