Jonas Danielsson is my 4th Great Grandfather. He was born on 29 Aug 1741, the son of Daniel Thorsson and Karin Jonsdotter, in Linneryd, Kronoberg, Sweden. I know very little about him. He married Helena Johansdotter on 18 Jun 1775 in Linneryd. They had a son named Daniel and a stillborn child in 1783. Helena also died at or following that birth. Jonas remarried three years later on 18 Apr 1786 in Almeboda, Catharina Jacobsdotter. They had seven children, two of whom died as infants. Their first son and second child was Magnus Jonasson, my 3rd Great Grandfather. About 1800 the family moved to Nobbele, Kronoberg, where Jonas died on 23 Jan 1807 at the age of 66 of "breast fever" (brostfeber) or pneumonia.
In the early days of my genealogy research, in 1979, I went to the LDS Family History Library in Los Angeles a number of times. They have a very large library of microfilms and such. I found a microfilm of parish records for Dadesjo, Kronoberg, Sweden. This is where my Great Grandfather, Adolph Peterson, Magnus' grandson, was born. I found his birth record, his parents wedding record and I thought I found Magnus' birth record. I went on from there and put it all on my tree. Years later, in 2009, I posted my tree on Ancestry. A man who was also descended from Magnus sent me a message that he had a totally different set of parents for Magnus. He had gotten it from a tree posted on line and he sent me the url. I contacted the Swedish man who had posted the tree and asked how he knew that he had the right ancestors for Magnus. He sent me a copy of the Husforhors, or household record that showed Magnus and his family. This said that Magnus was born in Linneryd, not Dadesjo. There was no arguing with it as it showed Magnus with the wife I knew was correct and the children including one that I knew to be my 2nd Great Grandmother. He also sent me a copy of the whole tree which was fabulous! He was descended from my 2nd Great Grandmother's brother. I sent him some data about her which he didn't have. This enabled me to correct my tree and discover Jonas Danielsson on it.
What I learned is that just the same name is not enough to make an identification, especially in Sweden where there were few family names but just each child taking the first name