Where did general lee surrender to general grant which offially ended the civil war?

He surrendered at Appomattox Court House on April 9th 1865. It did not officially end the war. It was only an armistice. And other Confederate units were still in action for a few weeks beyond that date. But this is taken as the effective end of hostilities.

The war never officially ended, because Congress did not recognise the Confederacy as a sovereign nation, and there had never been an official declaration of war.

As the Confederacy formally wound-up at its last cabinet meeting on May 10th 1865, that date could be taken as the notional ending of the war.