How Arizona's borders were drawn: from the Mexican Cession to statehood
Grade 8 Social Studies Worksheet

Circle the best answer.
Read this first
Gadsden Purchase: a State Department history
Who made it: the Office of the Historian, US Department of State. When: today. Where: Washington, DC. For whom: readers today. Why: to explain the history of US foreign relations. Summary in our words, not a quotation: A southern railroad route had to cross Mexican land, and both countries claimed the Mesilla Valley. Santa Anna, Mexico's president, did not want to sell a large part of Mexico but needed money to pay an army fighting rebellions. The treaty signed December 30, 1853 set $15 million for 45,000 square miles. The Senate, divided by strife between northern and southern states, ratified a revised treaty on April 25, 1854: $10 million for 29,670 square miles. A later dispute over the payment followed.
Ari asks how the 1853 deal looked from each side. Which pairing matches the card?
- United States: money for an army; Mexico's president: a railroad route
- United States: a railroad route; Mexico's president: money for an army
- United States: protecting Native nations; Mexico: ending a war
- Both governments wanted the railroad route most
The Gadsden Purchase, 1853 and 1854
Map 1, "Before the purchase" (1853): The border runs along the Gila River. Both countries claim the Mesilla Valley. The United States wants a southern route for a railroad across the continent, which must pass through Mexican land. Map 2, "After the Gadsden Purchase" (1854): The border moves south. The United States gains 29,670 square miles south of the Gila River, land that becomes part of Arizona and New Mexico. Key: orange: Mexico; blue: the United States; green: the land bought in the Gadsden Purchase. Below the maps: James Gadsden and Mexico's President Antonio de Santa Anna signed a treaty on December 30, 1853, for $15 million and 45,000 square miles. The US Senate ratified a smaller, revised treaty on April 25, 1854: $10 million for 29,670 square miles. The Tohono O'odham claim ancestral lands on both sides of the new border, and Yaqui people live on both sides too.
Bo asks which chain of causes the 1853 and 1854 maps and note support.
- The 1853 treaty, then a war with Mexico, then the border on the Gila River
- The 1848 treaty promised a railroad, and the 1853 treaty kept the promise
- The border on the Gila River, then the 1853 treaty, with the railroad playing no part in it
- Border on the Gila River, then a route through Mexican land, then the purchase
Gadsden Purchase: a State Department history
Who made it: the Office of the Historian, US Department of State. When: today. Where: Washington, DC. For whom: readers today. Why: to explain the history of US foreign relations. Summary in our words, not a quotation: A southern railroad route had to cross Mexican land, and both countries claimed the Mesilla Valley. Santa Anna, Mexico's president, did not want to sell a large part of Mexico but needed money to pay an army fighting rebellions. The treaty signed December 30, 1853 set $15 million for 45,000 square miles. The Senate, divided by strife between northern and southern states, ratified a revised treaty on April 25, 1854: $10 million for 29,670 square miles. A later dispute over the payment followed.
A student writes, "The United States paid $15 million for the Gadsden land." Esme checks the card. What is the problem?
- The Senate raised the price from $10 million to $15 million
- Nothing is wrong, because the card gives a price of $15 million for the land
- $15 million was the price of the 1854 treaty, signed by the Senate
- That was the first price; the treaty the Senate ratified paid $10 million
Treaty of Guadalupe Hidalgo, Article VIII (part)
Who made it: Negotiators for the United States and Mexico. When: Signed February 2, 1848. Where: Guadalupe Hidalgo, Mexico. For whom: the two governments and the Mexican residents of the ceded land. Why: to end the Mexican-American War and set the terms of peace. Excerpt (Treaty of Guadalupe Hidalgo (1848), Article VIII, English text; National Archives transcript): "…But they shall be under the obligation to make their election within one year from the date of the exchange of ratifications of this treaty; and those who shall remain in the said territories after the expiration of that year, without having declared their intention to retain the character of Mexicans, shall be considered to have elected to become citizens of the United States." Source card "Article IX of the treaty, summarized". Who made it: the National Archives, summarizing the treaty text. When: today. Where: Washington, DC. For whom: readers today. Why: to explain what the treaty said. Summary in our words, not a quotation: Article IX covers Mexicans who did not keep Mexican citizenship under Article VIII. They were to be incorporated into the Union, and admitted to full US citizenship at the proper time, as Congress judged. Until then, their liberty, property and religious freedom were to be protected.
Jun reads Article VIII and the Article IX summary together. Which statement joins them correctly?
- Residents who stayed became full citizens the moment they chose, with no later step
- Residents who kept Mexican citizenship had to leave the territory
- Congress decided in the first year whether residents could stay or had to go
- Residents chose within a year; Congress later decided when full citizenship came
Arizona's 1906 vote
Who made it: the Law Library of Congress, in its In Custodia Legis blog. When: February 2022. Where: Washington, DC. For whom: readers today. Why: to mark Arizona's statehood anniversary. Summary in our words, not a quotation: In November 1906 Arizona voters rejected joint statehood with New Mexico, 16,265 to 3,141. Arizona became the 48th state on February 14, 1912, the last of the contiguous states to join. Source card "Taft's 1911 veto". Who made it: the National Archives, Center for Legislative Archives. When: today. Where: Washington, DC. For whom: readers today. Why: to explain a document in its collection. Summary in our words, not a quotation: On August 15, 1911, President Taft vetoed the statehood resolution in large part because Arizona's constitution allowed the recall of judges.
Luz compares the two cards. Which statement about the delay in Arizona's statehood do both support?
- Decisions made in Washington alone delayed Arizona statehood
- Arizona voters caused the 1911 veto by rejecting joint statehood
- Taft alone decided the date, and voters had no part
- Choices made in Arizona and in Washington both delayed statehood
Taft's 1911 veto
Who made it: the National Archives, Center for Legislative Archives. When: today. Where: Washington, DC. For whom: readers today. Why: to explain a document in its collection. Summary in our words, not a quotation: On August 15, 1911, President Taft vetoed the statehood resolution in large part because Arizona's constitution allowed the recall of judges.
Milo wants Taft's exact reasons in 1911. Which source is best for that?
- This card, because a government archive makes it primary
- The text of Taft's August 15, 1911 veto message
- A map of Arizona from 1912
- A timeline card that gives the statehood date
The Gadsden Purchase, 1853 and 1854
Map 1, "Before the purchase" (1853): The border runs along the Gila River. Both countries claim the Mesilla Valley. The United States wants a southern route for a railroad across the continent, which must pass through Mexican land. Map 2, "After the Gadsden Purchase" (1854): The border moves south. The United States gains 29,670 square miles south of the Gila River, land that becomes part of Arizona and New Mexico. Key: orange: Mexico; blue: the United States; green: the land bought in the Gadsden Purchase. Below the maps: James Gadsden and Mexico's President Antonio de Santa Anna signed a treaty on December 30, 1853, for $15 million and 45,000 square miles. The US Senate ratified a smaller, revised treaty on April 25, 1854: $10 million for 29,670 square miles. The Tohono O'odham claim ancestral lands on both sides of the new border, and Yaqui people live on both sides too.
Noah compares the two maps. Which statement about the Gila River is supported?
- It marked the border in 1845, and Mexico owned the land north of it
- It marked the border in 1853, and the Gadsden land lay south of it
- It marked the whole border between the two countries
- It marked the border in 1854, with the Gadsden land to its north
Gadsden Purchase: a State Department history
Who made it: the Office of the Historian, US Department of State. When: today. Where: Washington, DC. For whom: readers today. Why: to explain the history of US foreign relations. Summary in our words, not a quotation: A southern railroad route had to cross Mexican land, and both countries claimed the Mesilla Valley. Santa Anna, Mexico's president, did not want to sell a large part of Mexico but needed money to pay an army fighting rebellions. The treaty signed December 30, 1853 set $15 million for 45,000 square miles. The Senate, divided by strife between northern and southern states, ratified a revised treaty on April 25, 1854: $10 million for 29,670 square miles. A later dispute over the payment followed.
Pia is asked which statement goes beyond what the card supports. Which should Pia pick?
- The purchase ended all disputes between the two countries
- Both countries had claimed the Mesilla Valley
- The Senate approved a smaller treaty than the one first signed
- The United States wanted a railroad route through Mexican land
Griffith on the Arizona-Sonora border
Who made it: James S. Griffith, a folklorist writing for the Smithsonian Folklife Festival. When: 1993. Where: Washington, DC. For whom: festival visitors and readers. Why: to describe the border region and its peoples. Summary in our words, not a quotation: The Tohono O'odham claim ancestral lands on both sides of the border. Yaqui people live on both sides too. The lands to the north were occupied most particularly by the Apaches. Source card "Treaty of Guadalupe Hidalgo, Article VIII (part)". Who made it: Negotiators for the United States and Mexico. When: Signed February 2, 1848. Where: Guadalupe Hidalgo, Mexico. For whom: the two governments and the Mexican residents of the ceded land. Why: to end the Mexican-American War and set the terms of peace. Excerpt (Treaty of Guadalupe Hidalgo (1848), Article VIII, English text; National Archives transcript): "…But they shall be under the obligation to make their election within one year from the date of the exchange of ratifications of this treaty; and those who shall remain in the said territories after the expiration of that year, without having declared their intention to retain the character of Mexicans, shall be considered to have elected to become citizens of the United States."
Tala asks why Griffith's 1993 card cannot show what the 1848 negotiators intended.
- It describes the region in 1993 and does not record their plans
- Griffith writes to argue against what the treaty did
- The card is about a different country
- A card made in 1993 is too recent to count as a historical source
The treaty: what the National Archives says
Who made it: the National Archives, describing the treaty. When: today. Where: Washington, DC. For whom: readers today. Why: to explain a milestone document. Summary in our words, not a quotation: The treaty, signed February 2, 1848, ended the Mexican-American War. Mexico ceded 55 percent of its territory, an area of more than 525,000 square miles, including most of present-day Arizona. The United States paid Mexico $15 million. Source card "Gadsden Purchase: a State Department history". Who made it: the Office of the Historian, US Department of State. When: today. Where: Washington, DC. For whom: readers today. Why: to explain the history of US foreign relations. Summary in our words, not a quotation: A southern railroad route had to cross Mexican land, and both countries claimed the Mesilla Valley. Santa Anna, Mexico's president, did not want to sell a large part of Mexico but needed money to pay an army fighting rebellions. The treaty signed December 30, 1853 set $15 million for 45,000 square miles. The Senate, divided by strife between northern and southern states, ratified a revised treaty on April 25, 1854: $10 million for 29,670 square miles. A later dispute over the payment followed.
Zee compares the 1848 and 1853-54 border changes. Which similarity do the cards support?
- Both ended a war between the United States and Mexico
- Both added land to the United States, and Mexico was paid
- Both added land north of the Gila River to the United States
- Both added the same amount of land