An 1830 merchant's account book shows that after the Erie Canal opened in 1825, shipping a barrel of flour from Buffalo to New York City cost far less than by wagon. Which cause of the canal towns' growth does this evidence support?

A Kansas town's records show its population doubled in the same year a railroad line reached it, and that cattle driven up from Texas were loaded there for eastern markets. Which cause of the town's growth does the record support?

In an 1847 letter, a woman on the Oregon Trail writes that her family left Missouri for free land, rich soil, and a milder climate she had read about. Which cause does the letter NOT support?

A timeline shows the transcontinental railroad completed in 1869 and the telephone invented in 1876. An 1870 newspaper says goods now arrive from the East in days instead of weeks. Which cause can explain that change?

A colonist's 1608 account of Jamestown says that most men spent their days digging and washing for gold while few planted corn. Which cause of the colony's food shortage does this account support?

A letter carried by an Irish family who sailed for America in 1847 reads, "The potato crop has failed again and there is nothing left to eat." Which cause of their emigration does the letter support?

A 1774 colonial pamphlet argues, "We are taxed by a Parliament in which we choose no members." Which cause of colonial anger does this source directly support?

A county report from 1936 states that no rain fell during three summers and that plowed topsoil blew away in the wind. Which cause of families leaving these Plains farms does the report support?

A student writes, "The city grew so large that the wide river appeared beside it." What mistake about cause and effect does this sentence show?

On a timeline, an event can only be a cause of another event if it happened earlier in the sequence.

When historians weigh causes, what are they trying to decide?

True or False: A major event can have more than one cause.

A 1959 city inspection report found that the steel beams supporting the Main Street Bridge were rusted through and could collapse under heavy loads. Which cause of the town's decision to replace the bridge does this report support?

Which question best helps you decide whether a cause was important?

Colonists had several complaints against Britain before the American Revolution. Which complaint was most directly about money?

True or False: The cause that happened first is always the most important cause.

A family moves west in the 1800s because farmland is cheaper, relatives are already there, and the trip sounds exciting. Which reason is most likely an economic cause?

Which is the best example of weighing causes instead of just listing causes?

A 2020 school newsletter reports that the district started requiring recycling bins in every classroom the same month a new state law took effect requiring schools to cut landfill waste. Which cause of the program's start does the newsletter support?

True or False: Evidence, such as letters, laws, maps, or photographs, can help historians judge which causes were important.