Complex sentence: While many did, the Metropolitan Museum of Art failed to do so which led to picketing by an offshoot, led by Robert Morris and Poppy Johnson, under the name "Art Strike Against Racism, War and Oppression".
Split into simpler sentences: While many did, the Metropolitan Museum of Art failed to do so. This led to picketing by an offshoot, led by Robert Morris and Poppy Johnson, under the name "Art Strike Against Racism, War and Oppression".