By the 1820s, soon after Mexico became independent of Spain, wagon loads of traders were pushing southwest, cutting deep ruts in a path that was called the Santa Fe Trail . In 1831 Josiah Gregg traveled the trail with 100 wagons. Finally he arrived in Santa Fe, as he described: "The arrival produced a great deal of bustle and excitement among the natives. 'Los Americanos!' 'Los carros!' … [was] heard in every direction; and crowds of women and boys flocked around to see the newcomers ."

Only a few American women had traveled the Santa Fe Trail in 1846 when eighteen-year-old Susan Magoffin headed west from Missouri. Newly married and pregnant, she was excited by the adventure. From her tent on the trail she wrote these words: "Oh this is a life I would not exchange for a good deal! There is such independence, so much free uncontaminated air, which impregnates the mind, the feelings, nay every thought, with purity. I breathe free without that oppression and uneasiness felt in the gossiping circles of a settled home."

They had ancestors who had hugged parents and grandparents, wiped away tears, and set out for a New World. Now another generation of men, women, and children was heading west, toward a little-known world, where land was free and fertile and opportunity seemed to be waiting. They were going for the reasons that usually make people move: because they wanted a better life for themselves and their children, or because they were adventurous or restless . One Missouri farmer wrote home to explain why he was taking the Oregon trail northwest: "Out in Oregon I can get me a square mile of land. And a quarter section for each of you all. Dad burn me, I am done with the country. Winters it's frost and snow to freeze a body; summers the overflow from Old Muddy drowns half my acres; taxes take the yield of them that's left. What say, Maw, it's God's country ."

In 1835 a young Frenchman named Alexis de Tocqueville wrote of "the holy cult of freedom" he encountered everywhere he traveled in America. He wrote: "Do not ask me to analyze this sublime sentiment; it must be felt. It enters of itself into … hearts … prepared to receive it; it fills them; it enraptures them."

People were coming to America from all over the world. Mostly these immigrants knew little about America except that it was a land of freedom. But that was what they wanted: freedom and a chance to work.

A Norwegian immigrant put it this way: "I feel free and independent among a free people … and I am very proud of belonging to a mighty nation, whose institutions must in time come to dominate the entire civilized world."