Dennis, I haven't found anything as to why so many of them came in 1850's. What is weird is My Moses Alvin Spring went back to Tennessee in the 1850's and then came back to Illinois later on in the 1850's. Here is something else, when he went back to Tennessee he didn't go back to Wilson county he instead went to Warren Co. There is a Thomas B. Spring that is a doctor that is listed there. Moses Alvin's oldest son is named Thomas B. Spring. Thomas B. Spring (the doctor) may be the oldest son of the older Moses Spring. I haven't reseached Warren co. for any other Spring's.