How can i find a old life insurance policy issued by the Occidental Life Insurance in the over 70 years ago in Illinois?

Before an insurance company can sell insurance in a certain state, it must register with the State Dept of Insurance. If the company is sold, then it must notify the Dept of who it was sold to. If it just closes down, its policies were likely sold to another company, the Dept will have to be notified of that as well.

Contact the IL Dept of Insurance and inquire there.