Final answer:
The Constitutional Union Party did not make slavery a key issue. Lincoln and Douglas were trying to win the Northern vote. Douglas and Breckinridge were trying to win the Southern vote.
Step-by-step explanation:
The first statement is false. The Constitutional Union Party, also known as the Bell-Everett Party, sought to preserve the Union and maintain the status quo rather than take a strong stance on the issue of slavery.
The second statement is true. Both Abraham Lincoln and Stephen Douglas were politicians who vied for the support of Northern voters during the 1860 presidential election.
The third statement is also true. John Breckinridge and Stephen Douglas were both contenders for the Southern vote. Breckinridge represented the Southern Democrats, while Douglas represented the Northern Democrats.
Learn more about Political parties and presidential election of 1860