Scandinavian-American Lutheranism is actually my focus in doctoral studies. Most of what has been said here is accurate, but I would like to add a couple of things and clarify one point in particular.
Yes, the "little Norwegians" are the group from the Norwegian Synod that refused to join the merger of Hauge's Synod, the United Norwegian Lutheran Church, and the Norwegian Synod in 1917. The reason behind their refusal was their unwillingness to affirm the Madison Agreement of 1912, which allowed for two different interpretations of the doctrine of election to coexist in a unified Norwegian Lutheran church body. The new denomination began with the title "the Norwegian Lutheran Church of America" (NLCA). They changed the name of the denomination in 1946, after World War II, in order to reflect the American character of the church body. The new title was the "Evangelical Lutheran Church." So, this "big" church body, which reached about one million members in the 1950s, was rightfully called "the big Norwegians." The "little Norwegians" were connected with the Missouri and Wisconsin Synods, along with a few smaller groups, in a cooperative federation called "the Synodical Conference." This was an alternative to other cooperative Lutheran federations such as the National Lutheran Council and the American Lutheran Conference.
I wouldn't say that Norwegians and Swedes "didn't get along." The situation is much more complicated than that. In 1853, a group of both Norwegians and Swedes joined the Synod of Northern Illinois and together left that synod in 1860 due to a lax attitude toward confessional subscription. All they could muster was a claim that the Augsburg Confession was "mainly correct." The Scandinavians together formed a group called the "Scandinavian Augustana Synod" in 1860. They called a Scandinavian professor, Lars P. Esbjorn, to teach at their seminary. After ten years, however, linguistic and cultural issues led to the amicable departure from the Swedes. It was clear that there were not ill feelings. The Norwegians that left in 1870 split right away into two groups. The larger was known as "the Conference of the Norwegian Evangelical Lutheran Church," or simply "the Conference." The smaller group was the "Norwegian Augustana Synod." In 1890, those two groups joined together anyway along with a group from the Norwegian Synod known as the "Anti-Missourian Brotherhood." That was the merger that formed the United Norwegian Lutheran Church.
I disagree with Pr. Austin's assertion that the Swedes brought with them their historic acceptance of episcopacy. There were isolated voices throughout the years within the Augustana (Swedish) Synod for the acceptance of historic succession, but the Swedes in that body mostly rejected any claim to be in Swedish historic succession. Swedish immigrants came to the US for many of the same reasons that Norwegians did: financial, mostly. Though in both countries there was resentment of the establishment, including religious establishment. And it should also be noted that the majority of both Swedes and Norwegians, and Danes as well, did not join Lutheran churches in America.
When the Archbishop of Sweden, Nathan Soderblom, visited the US in the 1920s, he presented a pectoral cross to the president of the Swedish Augustana Synod as a sign of friendship. Although it was accepted, it was accepted with the caveat that "we do not hereby adopt any understanding of apostolic succession in our church body" (paraphrase). There was a strong desire among the Swedish American Lutherans to distance themselves from the State Church of Sweden.
Big topic. Lots more to say, but I'll end it for now.
