$("#benefits-page").fadeIn(750);
works immediately because it starts when the first element (# solar-about in your example) has completed the fadeOut animation.
If you want to wait for all animations to complete, you can use . prom () , for example:
$("#solar-about, #home-page, #process-page, #financing-page, #vendors-page, #consump-info-page, #smart-page, #wind-page, #about-page").fadeOut(750).promise().done(function() { $("#benefits-page").fadeIn(750); });
Demo
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