Definition of Annexation
Definition of Annexation: Annexation means adding or incorporating a territory previously outside its jurisdiction as in as, the annexation of Texas to the United States of America.

Texas Annexation for kids: Background History
The application of Texas Annexation and its admission to the Union was supported by the slave states of the south. As a part of the Mexican Republic Texas had been free soil but, as the climate was well suited to production of the cotton plant, and it would surely be admitted as a slave state. The issue of admitting Texas to the union first came before President Andrew Jackson. Jackson knew that the admission of Texas would be strongly opposed by the slave free states of the North, so he did not press the issue. President Martin Van Buren had not opposed the acquisition of Texas but did nothing to aid annexation. President John Tyler did take action and under his direction a treaty was draft providing for the admission of Texas to the Union, but the Senate refused to ratify the treaty.

Texas Annexation for kids: Background History
The Texas Annexation President John Tyler preempted James Polk on the issue of the Texas Annexation by drafting the proposals on 27 February, 1844 and presenting the bill to annex Texas on March 1, 1845. Before Texas was actually admitted Tyler had ceased to be President, but James Polk continued to support the policy. Texans approved of the popular bill which was signed by President James Polk on December 29, 1845, admitting Texas as the 28th state of the Union by joint resolution.

Texas Annexation Timeline and Facts for kids
The Annexation Facts and Timeline for kids is detailed below. The history of the Annexation is told in a factual timeline sequence consisting of a series of short facts providing a simple method of relating the famous people and events surrounding the Annexation of Texas. 

1821: The Mexicans won their independence from Spain and founded the Mexican Republic. Immigrants from the US settled in the northeastern part of the new republic - which was called Texas

1829: President Jackson offers to purchase Texas, for $1 million. Mexican President Vicente Guerrero declines

April 6, 1830: The Mexican government bans US immigration

October 2, 1835: The Texas Revolution began with the battle of Gonzales against the Mexican forces under Santa Anna

March 2, 1835: Texas declares independence from Mexico

November 1835: Sam Houston was selected as Commander-in-Chief of the Texan Army

February 23, 1836 – March 6, 1836: The Battle of the Alamo, a 13 day siege at a mission in San Antonio that saw the death of 180 Americans including Davy Crocket, Jim Bowie and Colonel William B. Travis

September, 1836: Texans submit the application of Annexation and its admission to the Union

March 27, 1836: The Goliad Massacre in which 350 Texan prisoners, and their commander James Fannin, were executed by Mexican forces

April 21, 1836: Battle of San Jacinto, the last battle of the Texan Revolution

April 22, 1836: General Santa Anna is captured

May 14, 1836: The peace treaty of Velasco is signed by the Texan Republic and Santa Anna for Mexico

September, 1836: Texans vote overwhelmingly in favor of annexation and Sam Houston is named President of the Republic on October 22, 1836:

January 11, 1837: Resolution to recognize Texas is introduced in the U.S. Senate

March 3, 1837: United States recognizes the Republic of Texas

1838: Mirabeau Lamar succeeds Houston as the Texan Republic President

October 12, 1838: Texas withdraws the offer of annexation because of the lack of action by the US Congress

1841: Sam Houston serves a second term as the Texan President

June 15, 1841: Sam Houston issues proclamation declaring armistice between Mexico and Texas.

January 1844: President Sam Houston submits annexation instructs minister to the U.S. to resume annexation talks

27 February, 1844: Annexation proposals are drafted

1844: Anson Jones is sworn in as President of the Texan Republic

March 1, 1844: Annexation treaty presented to the Senate

June 8, 1844: U.S. Senate rejects the treaty, 35 to 16

March 1, 1845: Congress passes a "Joint Resolution for Annexing Texas to the United States", The resolution is signed by President Tyler. March 3, 1845: Annexation offer sent to Texan president Anson Jones

March 4, 1845: James Polk becomes US President

1845: John O’Sullivan initiates the phrase 'Manifest Destiny'

May 19, 1845: Cuevas-Smith treaty between Mexico and Texas is signed guaranteeing Texans independence as long as it remains a separate republic

October 13, 1845: Annexation ordinance and state constitution submitted to the Texan voters for approval

December 29, 1845:  President Polk signs the Joint Resolution admitting Texas as the 28th state of the Union.

Texas Annexation for kids - Border Dispute with Mexico
The Republic of Texas had claimed land up to the Rio Grande based on the Treaties of Velasco, but Mexico refused to accept the Treaties of Velasco as valid, claiming the border as the Nueces River. The border disputes caused the outbreak of the Mexican–American War.

Texas Annexation for kids - Mexican–American War
The Mexican–American War was a military conflict fought between Mexico and the United States from April 25, 1846 – February 2, 1848. The war ended when the 1848 Treaty of Guadalupe Hidalgo was signed which established the southern boundary of Texas at the Rio Grande.