In my particular family they were in Jasper Co in mid 1850's but wre back in Illinois in 1860. Missouri was middle ground between slave and free states and there were orders to clearn a strip in 1860 so many fmailies went back to their original homes. Know my family had came to Missouri to claim land from grants for War of 1812 soldiers and their widows. Mining did not really start big in this area until early 1870's