Erik Magnus Berglund can be followed through Folkräkningar (census) from 1870 to 1910. You can see in Arkiv Digital that he leaves home in 1870 to go to Älvsbyn Parish. Piteå landsförsamling AI:10a (1862-1870) Bild 299 / sid 290 (AID: v138599.b299.s290, NAD: SE/HLA/1010154)
So in the census for 1870 he is a farm hand in Älvsbyn, still single.
In 1880 he is a sawmill worker in Ytterstfors, Byske parish. He is married to Helena Viksten, born 1847 in Byske. Their first two children are in the census.
In the census for 1890 they are still in Ytterstfors. Here we get all the children:
Namn Berglund, Erik Magnus
Hemförsamling Byske
Hemort Ytterstfors sågverk
Län Västerbotten
Födelseår 1849
Födelseförsamling Piteå
Yrke arbetare
Upprättad av Riksarkivet SVAR-Svensk arkivinformation
Personer i hushållet
Berglund, Erik Magnus, f. 1849 i Piteå, arbetare
Viksten, Helena, f. 1847 i Byske Västerbottens län
Gustaf Elis, f. 1878 i Byske Västerbottens län
Elin Helena, f. 1879 i Byske Västerbottens län
Frans Emil, f. 1881 i Byske Västerbottens län
Erik Arvid, f. 1883 i Byske Västerbottens län
John Magnus, f. 1885 i Byske Västerbottens län
In 1900 they are at another sawmill in Byske parish: Furuögrund. The older children are beginning to move out. In 1900 still in Furuögrund, with only Erik Arvid still at home. You can see these locations here.