The December 12th USPS Postal Bulletin indicates that this issue will be released January 31st, probably in Brooklyn, NY. (The scratch image shown here was taken from the postmark sample files.)

From my article from the October press preview:

Also of note is next year’s Black Heritage subject: Congresswoman Shirley Chisholm, the first African-American woman elected to Congress. What’s also notable is that the series will again be available for Black History Month (February). 2013’s Althea GIbson stamp was issued in August, 2011’s Barbara Jordan was in September. The Chisholm stamp is a portrait by artist Robert Shetterly.

Here are the Digital Color Postmark and black-and-white pictorial postmark for this issue:

How to Order the First-Day-of-Issue Postmark:
Customers have 60 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office, at The Postal Store® website at www.usps.com/shop, or by calling 800-STAMP-24. They should affix the stamps to envelopes of their choice, address the envelopes (to themselves or others), and place them in a larger envelope addressed to:

Shirley Chisholm Stamp

Retail Manager
1050 Forbell Street
Brooklyn, NY 11256-9998

After applying the first-day-of-issue postmark, the Postal Service will return the envelopes through the mail. There is no charge for the postmark up to a quantity of 50. For more than 50, customers have to pay five cents each. All orders must be postmarked by April 2, 2014.

There is a special postmark available for local post offices to use:Technical Specifications:
Issue: Shirley Chisholm Stamp
Item Number: 471600
Denomination & Type of Issue: First-Class Mail Forever Commemorative
Format: Pane of 20 (1 design)
Series: Black Heritage
Issue Date & City: January 31, 2014, Brooklyn, NY 11201
Designer: Ethel Kessler, Bethesda, MD
Art Director: Ethel Kessler, Bethesda, MD
Typographer: Ethel Kessler, Bethesda, MD
Existing Art: Robert Shetterly
Engraver: WRE
Modeler: CCL Label, Inc.
Manufacturing Process: Gravure
Printer: CCL Label, Inc.
Printed at: Clinton, SC 29325
Press Type: Dia Nippon Kiko (DNK)
Stamps per Pane: 20
Print Quantity: 33.5 million stamps
Paper Type: Phosphor Tagged, Block; Nonphosphored, Type III
Adhesive Type: Pressure-sensitive
Processed at: CCL Label, Inc., Clinton, SC
Colors: Cyan, Magenta, Yellow, Black
Stamp Orientation: Vertical
Image Area (w x h): 0.84 x 1.42 in./21.34 x 36.07 mm
Overall Size (w x h): 0.98 x 1.56 in./24.89 x 39.62 mm
Full Pane Size (w x h): 5.85 x 7.25 in./148.59 x 184.15 mm
Plate Size: 200 stamps per revolution
Plate Numbers: “C” followed by four (4) single digits
Marginal Markings:
Front: Header: “BLACK HERITAGE” • “37TH IN A SERIES • Plate numbers in four corners of pane
Back: ©2013 USPS • Verso text • USPS logo • Plate position diagram • Barcode (471600) in upper right and lower left corners of pane • Promotional text