Decide which cause mattered most, and say why
Grade 7 Social Studies Worksheet
Circle the best answer.
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The Dust Bowl (cards A to C; summaries in our words). Card A, weather: in the 1930s the southern Great Plains had a long drought, and strong winds blew across the open land. On April 14, 1935, a huge dust storm, remembered as Black Sunday, darkened the sky across the region. Card B, farming: the roots of prairie grass held the soil in place. In the 1910s and 1920s, when wheat prices were high, farmers plowed up millions of acres of prairie grass to plant wheat. When the drought came, much of that land had no grass or crop to hold the soil. Card C, the response: in 1935 the United States government created the Soil Conservation Service. Farmers were taught to plant rows of trees as windbreaks and to plow along the curves of a slope. Rain returned around 1939 to 1941, and the storms eased.
Which statement best weighs drought against plowing as causes, Ari asks?
- Drought explains the dust storms, because plowing is not on card A
- Drought was the trigger, and plowing left soil bare: both mattered
- Plowing explains the storms, because high wheat prices caused it
- Neither mattered, because wind alone moved the soil
Black Sunday was in 1935, and rain returned around 1939 to 1941. About how many years later did rain return, Bo asks?
- About 24 to 26 years
- About 14 to 16 years
- About 3,874 to 3,876 years
- About 4 to 6 years
A student says, "Card A proves the drought alone caused the dust storms." How strong is that claim, Esme asks?
- Strong: card A says the storms began in the 1910s with the first plowing
- Weak: card B shows bare plowed land mattered too
- Strong: card A names the drought and the wind, which is enough to explain it
- Weak: weather cannot cause a dust storm, just people can
Which order of causes fits cards A and B, Jun asks?
- High prices led to plowing; drought and wind then moved bare soil
- Wind lifted the soil first and high wheat prices then followed
- High wheat prices led straight to dust storms, with nothing between
- Drought came first and farmers then plowed up the grass to plant wheat
Which cause could farmers have changed before the drought, Kira asks?
- The drought, by choosing to plant a different crop each year
- How they used the land: plowing grass up and leaving soil bare
- The wind, by planting rows of trees before the 1910s began
- The price of wheat, by agreeing together to sell it for less money
Cards A and B together explain why strong winds moved so much soil. What is the best statement, Luz asks?
- Winds crossed open land where plowing had removed the grass
- Winds were strong enough to move soil from any land, grass or not
- Winds blew more because plowing makes the wind stronger
- Winds carried the soil because farmers had burned the prairie grass
Records show less soil blew away from farms that kept grass in place during the same drought. What does that support, Milo asks?
- Card B: land cover mattered, not only weather
- That the wind did not blow on the farms that kept their grass
- That drought played no part in the dust storms
- That wheat prices fell during the 1930s
Suppose a farm of 640 acres had 75 percent of its prairie grass plowed up for wheat. How many acres were plowed, Pia asks?
- 715 acres
- 4,800 acres
- 160 acres
- 480 acres
A student says, "Card C proves the Soil Conservation Service ended the dust storms." How strong is that claim, Ren asks?
- Weak: a government service cannot affect what happens on farms
- Strong: the Service was created in 1935 and the storms eased afterward
- Weak: card C says rain also returned, so more than the Service helped
- Strong: card C says the Service brought back the rain
Which detail best supports the claim that farming practice was a cause, Zee asks?
- Card C: rain returned around 1939 to 1941 and storms eased
- Card A: strong winds blew across the open land of the plains
- Card A: Black Sunday darkened the sky across the region
- Card B: grass roots held the soil, and plowing took the cover