According to Article 1, Section 7 of the US Constitution:
If any Bill shall not be returned by the President within ten Days (Sundays excepted) after it shall have been presented to him, the Same shall be a Law, in like Manner as if he had signed it, unless the Congress by their Adjournment prevent its Return, in which Case it shall not be a Law.
Situations where the President refuses to sign the law and waits for Congress to adjourn instead are commonly called a "pocket veto". But has there been any law where the President refused to sign or veto the law, after which Congress didn't adjourn and the law still entered into force without a super-majority vote?