Why did nixon resign from office what were the circumstances?

President Nixon...the watergate scandal. 

Pres. Nixon's election committee broke into the DNC (Democratic National Committee's) headquarters attempting to wire-tap phones and steal classified documents, which would give his party (republican) a HUGE advantage in the election. However, this didn't last too long because their plans were discovered and Pres. Nixon decided to pay the thieves large sums of money to keep their mouths quiet. (This was called the Watergate Scandal because they broke into the Watergate Hotel, Washington D.C..

The media laid a massive load of pressure on him, and congress told him he would have to resign, or be impeached.

Nixon didn't want to be known as the first president to be kicked out, so he resigned to be remembered as the first president to resign from his current state in office.