According to the US Department of State's website, www.travel.state.gov (FAQ Section) you will receive your new passport and original citizenship documents as separate mailings.  You will likely receive your new passport book first and should then receive the documents you submitted to verify citizenship within 10 business days after this.

If you ordered both a passport book and card you may receive three separate mailings; one with your citizenship documents, one with your newly issued passport book, and one with your newly issued passport card.  This is because the passport book may be sent via 1-2 day service but the passport card must be sent via first-class mail.

If you do not receive your documents within this timeline, you should contact the National Passport Information Center (NPIC)

Phone: 1-877-487-2778/ 1-888-874-7793 (TDD/TTY)

Customer service representatives are available:    

Monday- Friday            8:00 a.m. to 10:00 p.m. Eastern Time
    Saturday                     10:00 a.m. to 3:00 p.m. Eastern Time
    *Except on Federal Holidays