Europeans migrating to the new world were seeking

The correct answer to this open question is the following.

Although you did not attach options for this question we can say the following.

Kennedy’s election made Americans optimistic because Jhon F.Kennedy promised a time for a benevolent change he called it "New Frontier."

He promised a new time for the United States full of positive changes in which the United States should become the leader that would help solve the internal problems as well as the problems of the world.

He had this discourse during his political campaign, in which he projected a radiant public image with the help of his wife Jackie Kennedy and a group of public relations experts that successfully managed his "radiant" image.

Those were the years of the Cold War, in which the American people had to hear something hopeful that kept their faith in US politics.