Although there are many resources on the Internet for genealogical research, the information is still limited. The farther you go back, the more difficult it will become to find information on your ancestors on-line.
This is where some letter writing skills will prove useful. Whether you use e-mail or snail mail, be polite. Please and Thank you can go a long way in helping you get the information you are seeking.
When using the mail always include a self-addressed, stamped envelope. When writing your letter, be to the point as possible about the information you are looking for. Be patient, many of the libraries and societies that you contact have limited staffing and it may take several weeks to get to your question.