Mark this question Which of the following factors contributed to many Americans voting strictly along party lines?

Several factors

Explanation:

Several factors influence party identification, and one of these factors is a person’s race. In the years following the Civil War, the majority of African Americans and Northerners favored the Republican Party. Many African Americans changed their party identification during the 1930s Depression Era, when they began supporting the Democratic Party and its New Deal policies. The 1960s civil rights movement marked another shift in which African Americans increasingly supported Democratic candidates at the polls. In the last half of the twentieth century, African Americans and Mexican Americans have tended to be Democrats. Conversely, other Hispanics such as Cubans have shown strong allegiance to the Republican Party.

Voting was a public affair, so people often felt pressure to vote in a particular way.

Explanation:

Usually, specific weekdays were set aside as holidays for each election, in order to allow men to assemble and vote. Since separate elections were held for local, state, and federal offices during this time, communities typically experienced at least two elections a year. Each election was preceded by public demonstrations and even the act of voting was a public affair. Where written ballots were used, rival political parties printed their respective ballot on paper of a certain color, which made it easy for them to see which party the people were voting for. Such an absence of secrecy contributed to strict party-line voting, in which most men in each community voted the same way.