My search began with a copy of a part of a family tree. I got it in that time from my father. Than I started a systematic search through several government archives in Overijssel and in Gelderland, and in the city archives of Zutphen and Amsterdam.

Sources
After some time I found a part of a family tree that was made by a famous genealogical, mr. W. Wijnaendts van Resandt. It was made in order by Mrs. Shirley Sleijster in California/USA. (click here...).
Besides I received much information from my brother Wout Sleijster, among other things a family tree that overlapped largely the here before mentioned tree. This one was made by Mr. J. Verdonk, an organizer of emigrant-journeys to the Dutch colonies in America (tree... and notes, acts...).

I also gathered lots of information from acts, certificates and books. I have tried to make a readable story and let the history live with this information.
I thank all these people, and also the many others who put data and material at my disposal or helped me in other ways.

Before 1811 the churches kept up the Baptism, Wedding and Bury books. The noted dates then are mostly the date of baptism, betrothal and burying, and not the date of Birth, Wedding and Death.

According to the documents the whole Sleijster family was Dutch Reformed (Nederlands Hervormd).

When in 1811 the Burgher State ("Burgerlijke Stand") is introduced, the reference to the church membership is unfortunately disappeared. From ± 1840 it is booked again in the Register of Population ("Bevolkingsregister"), that is a register per house.
So the Burgher State ("Burgerlijke Stand") is the register of the deeds that are made in the city hall with birth, wedding and death. Jot down are: the date, the names of the parents, spouses, occupation, age, place of birth, etc. These acts are not freely to see. But after a number of years the data are released. For birth certificates it is after 90 years, and for marriage certificates it is 80 years, and for decease it is 50 years.

So for the period after it, it is only by personal inquiry possible to collect the data. To get the data of the emigrated Sleijsters is of course much more difficult. So there is an uncultivated area.

From ± 1842 the cities keep up the so-called Register of Population ("Bevolkingsregister"). So is the register per house. You will find there the data of the inhabitants. It is mostly a family. The names, dates and places of birth, marriage, dead, occupation, and also the denomination. In ± 1938 the cities switch over to person cards, with the same data.