The Dutch US immigration from the 1800s produced at least two very cohesive communities that are very religious today, one in western Michigan (Holland-Grand Rapids) and two areas in Iowa, near Pella and Orange City.
I believe three main denominations survive today. The Reformed Church in America is now pretty mainstream, with women ministers, I believe.
The Christian Reformed Church is more conservative. I think they still prohibit women ministers, but use women in other roles. The Protestant Reformed Church is even more conservative.
This influence is so pervasive in Grand Rapids that the local joke several years ago was that even the Jews were Dutch Reformed.