Is the kind of military parade that President Trump wants ever been done for a US President before? Or done on US soil at all?

No, this is NOT a military tradition for our country. This is more in line with what the Russians, Chinese and North Koreans do; so dictatorships. Trump is trying to impress NK with our 'military might'. He is like a boy playing with toys.

Not just for the hell of it, normally only at the conclusion of a major war. Maybe he got the idea from watching TV coverage of the May Day parade in Moscow?

Yes it has. But it has usually happened in the context of victorious wars. The last time one happened was in 1991 after the victory in the Gulf War. They were also more common in the late 19th and early 20th centuries when the memory of the Civil War was still relatively fresh and important.

and you mocked the Barbarians what if you have another tenement square wouldn't it be hilarious