Read maps that show how borders and territory changed

Grade 8 Social Studies Worksheet

Circle the best answer.

1. Read this first

   Use this

   Texas, Oregon and the Rio Grande, 1845 to 1848 (cards A to C). Card A, a summary in our words from the State Department's Office of the Historian: Texas joined the United States on December 29, 1845. The Texans said their state extended to the Rio Grande, including large parts of what is now New Mexico and Colorado, while Mexico said the border reached only the Nueces River, north of the Rio Grande. In July 1845 President Polk ordered General Zachary Taylor to move into the land between the two rivers, and in November he sent John Slidell to Mexico to negotiate to buy the disputed areas. After skirmishes in the disputed land, the United States declared war on Mexico on May 13, 1846. The Treaty of Guadalupe Hidalgo was signed on February 2, 1848. Mexico ceded about 525,000 square miles, 55 percent of its prewar territory, for a $15 million payment, and the United States took on up to $3.25 million of debts that Mexico owed to U.S. citizens. Card B, the Treaty of Guadalupe Hidalgo, Article V (Avalon Project): "The boundary line between the two Republics shall commence in the Gulf of Mexico, three leagues from land, opposite the mouth of the Rio Grande, otherwise called Rio Bravo del Norte" and then run "from thence up the middle of that river, following the deepest channel, where it has more than one". Card C, the Oregon Treaty of 1846 with Great Britain (Avalon Project). Its opening says the governments wished that "the state of doubt and uncertainty which has hitherto prevailed respecting the sovereignty and government of the territory" should be ended "by an amicable compromise of the rights mutually asserted by the two parties". Article I says the boundary "shall be continued westward along the said forty-ninth parallel of north latitude to the middle of the channel which separates the continent from Vancouver's Island, and thence southerly through the middle of the said channel, and of Fuca's Straits, to the Pacific Ocean".

2. 1.

   Card A gives the Texan and Mexican claims. How do they differ, Ari asks?

   • Both said the border was the Rio Grande but disagreed about the date
   • The Texan claim was settled fact, since Texas had become a state
   • Texas claimed the Rio Grande; Mexico said the border was the Nueces River
   • Texas claimed the Nueces River; Mexico said the border was the Rio Grande
3. 2.

   A student says: "When Texas joined in 1845, the Rio Grande was the agreed border." How strong is that claim, given card A, Bo asks?

   • Weak: card A says Mexico disputed the border, holding it was the Nueces River
   • Strong: card B puts the Rio Grande in the 1848 treaty as the border
   • Weak: card A says Texas joined the United States in 1848, not in 1845
   • Strong: card A says Texas claimed land as far as the Rio Grande from the start
4. 3.

   Cards A and B both name the Rio Grande. What do they support together about the dispute, Esme asks?

   • The treaty showed that the Texan claim of 1845 had been right from the start
   • Card B shows that the Rio Grande was first named in 1848 by the treaty makers
   • The 1848 treaty started the boundary at the Rio Grande, the river Texas had claimed
   • The 1848 treaty started the boundary at the Nueces River, as Mexico had claimed in 1845
5. 4.

   Card A: Mexico ceded about 525,000 square miles, which was 55 percent of its prewar territory. About how large was prewar Mexico, Jun asks?

   • About 955,000 square miles, found by dividing 525,000 by 0.55
   • About 289,000 square miles, found by multiplying 525,000 by 0.55
   • About 525,000 square miles, because Mexico ceded its entire land
   • About 9,500 square miles, found by treating 55 percent as 5.5
6. 5.

   Card A: $15 million plus up to $3.25 million of debts for 525,000 square miles. About how much per acre in all (640 acres per square mile), Kira asks?

   • About 50 cents an acre, found by moving the decimal point wrongly
   • About 5 cents an acre, counting the payment and the debts
   • About 5 cents an acre, so Mexico accepted the offer of its own free will
   • About 4.5 cents an acre, counting the $15 million payment alone
7. 6.

   Using card A, which chain best explains how the border dispute led to the treaty, Luz asks?

   • Texas joined, Polk sent troops into the disputed land, skirmishes led to war, then a treaty
   • The Oregon Treaty of 1846 caused the war between the two countries over Texas
   • The treaty was signed first, and the war was then fought over the border that it set
   • The Treaty of Guadalupe Hidalgo caused Polk to send Taylor into the disputed land in 1845
8. 7.

   Card C's opening speaks of "doubt and uncertainty" about the territory. What is it best evidence for, Milo asks?

   • Both governments stated in the treaty that rights over the land were uncertain
   • Which government had the stronger claim to the land before the treaty
   • Nothing, because the opening of a treaty is a formal courtesy and has no meaning
   • Why the United States went to war with Mexico in the spring of 1846
9. 8.

   Card C moves from "doubt and uncertainty" to a named parallel and channel. What changed, Pia asks?

   • The two governments agreed to share the territory with no line drawn
   • A disputed territory received a line given by a parallel and a channel
   • The line ended each question about the northwest for good
   • A clear line became disputed, as the two governments asserted their rights
10. 9.

    Card A: Polk sent Taylor into the disputed land and sent Slidell to offer to buy it. What does the pairing suggest, Tala asks?

    • Slidell went first, and the troops followed after the talks had ended
    • Polk gave up the disputed land and sent Slidell to say so
    • Polk pursued the land by both military and diplomatic means
    • Polk wanted the strip between the two rivers and nothing more
11. 10.

    Card A comes from a U.S. State Department history office. What should a reader do to check the account of the dispute, Zee asks?

    • Compare it with Mexican sources, since a U.S. office tells it from the U.S. side
    • Throw it out, because a government office cannot be trusted on the subject
    • Treat it as a treaty text, because it is a government document with official status
    • Accept it as complete, because the office records both countries' claims