Emigration from The Netherlands peaked in the fifteen years after the second world war, triggered mostly by the rampant housing shortage. Emigration was actively encouraged by the Dutch government. The most popular destinations were Canada and Australia, and to a lesser extend the U.S., South Africa and New Zealand.
Tracing your roots into The Netherlands is relatively easy if you descend from these emigrants. Many of the emigrants are still alive, and even when they're not it is usually easy to find someone who has known them. You have probably some addresses of relatives in The Netherlands. On the other hand, most post-war archives are not accessible due to privacy regulations, so it may be harder to set the next step.
To fill the gap between the 1930s and your ancestor's emigration you should:
- Ask all your relatives for information. Someone will have information dating even further back.
- Check out family papers that you, or your relatives, still may have. There's probably a copy of your ancestor's birth certificate somewhere in your family, or maybe some letters from their relatives in the old country giving the clues you need.
- Write (or phone, or e-mail) your relatives in The Netherlands. Even if they don't have the information you need, they will know someone who has. Be persistent (but not annoyingly persistent).
- The Central Bureau for Genealogy (CBG) has information on almost anyone who lived and died in The Netherlands between 1939 and two to three years before now. They provide extracts for a fee. Contact them for details (ask for persoonskaarten).
- If all else fails, ask for help on the appropriate message board or forum.