AP U.S. History · Free-response skill

Back a causation thesis

The move. Support a causation thesis with specific, accurate evidence, explain how the cause worked, and add a second cause to make the argument more complete.

How to do it

  1. A causation thesis says what caused what. To support it, find evidence that shows the cause at work, not just evidence that the result happened.
  2. When you explain a cause, trace the steps: this changed, so that became possible, so the result followed.
  3. Show what made the cause possible. Big developments rarely happen alone; ask who paid for them, who built them and what rules helped.
  4. Then add complexity: name a second cause the thesis leaves out. A thesis that admits other causes and still argues its own is more convincing.
  5. Here is the move in a different setting: for the thesis "The cotton gin drove the spread of slavery into the Deep South", the rush of planters into Alabama and Mississippi after 1815 shows the cause at work, and the growing demand for cotton from British and New England mills is a second cause the thesis leaves out.
  6. This drill builds pieces of a long essay; a full essay also writes its own thesis, sets the context and develops the argument further.

Practice prompt Try it

Thesis to work with (written for this drill): Between 1865 and 1900, the growth of the railroads was the main cause of the rapid growth of American industry.

Use the thesis above to answer each part.

  1. Name one industry whose growth between 1865 and 1900 was driven by the railroads' own demand for its product.
  2. Explain how a national rail network let a business grow beyond its local market.
  3. Name one action of the federal government between 1862 and 1900 that helped railroads expand.
  4. Name one cause of industrial growth between 1865 and 1900 that is not the railroads.

Write each part, then check yourself against the checklist. Nothing you type here is saved or graded.

Check yourself and see a model answer

Checklist

Our own checklist of what a full answer does, one line per point. Tick each one your response earns.

0 of 4 points

Model answer, annotated

(a) The steel industry grew on the railroads' demand, because the railroads bought huge amounts of steel for rails, locomotives and bridges.

  • Point 1 Names steel, an industry the railroads bought from in large amounts.

(b) Railroads made it cheap and fast to ship goods across the country, so a business could sell far beyond its own town. Meatpackers such as Swift in Chicago used refrigerated rail cars to sell fresh beef in eastern cities.

  • Point 2 Cheaper, faster long-distance shipping let a business reach distant buyers, shown with Chicago meatpackers.

(c) The Pacific Railway Act of 1862 gave railroad companies land grants and government bonds to build the transcontinental line.

  • Point 3 A real, dated federal action that helped railroads: the Pacific Railway Act of 1862.

(d) Millions of immigrants supplied the cheap labor that filled new factories, mills and mines.

  • Point 4 A real cause other than railroads: immigrant labor.