From the U.S. Postal Service announcement on November 17, 2020:
From the USPS: This stamp celebrates the bicentennial of Missouri statehood. Missouri became the 24th state in the Union on Aug. 10, 1821. The stamp art is an existing photograph of Bollinger Mill State Historic Site by noted landscape photographer Charles Gurche. Art director Greg Breeding designed the stamp.
This stamp will be issued August 10th with a ceremony in Jefferson City, Mo.
Additional information will be posted below the line, with the most recent at the top.
Updated October 4th:
The Scott catalogue number for this issue is 5626.
Updated July 7th:
Here are the first-day postmarks for this issue: 
The Digital Color Postmark for this issue measures 2.60″ x 1.46″. 
The pictorial postmark measures 2.28″ x 1.24″
Updated July 1st from the Postal Bulletin:
On August 10, 2021, in Jefferson City, MO, the United States Postal Service® will issue the Missouri Statehood stamp (Forever® priced at the First-Class Mail® rate) in one design, in a pressure-sensitive adhesive (PSA) pane of 20 stamps (Item 481100). This stamp will go on sale nationwide August 10, 2021, and must not be sold or canceled before the first-day-of-issue.
This stamp celebrates the bicentennial of Missouri statehood. Missouri became the 24th state in the Union on August 10, 1821. The stamp art is a photograph taken of Bollinger Mill State Historic Site. The photo shows the multi-story mill, which dates to the Civil War period, as well as the Burfordville Covered Bridge, Missouri’s oldest covered bridge and one of only four that remain in the state. Noted landscape photographer Charles Gurche, who took this shot, began his photography career in Missouri. Art director Greg Breeding designed the stamp with an existing photograph by Gurche.
Automatic distribution only in Missouri.
How to Order the First-Day-of-Issue Postmark:
Customers have 120 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office™ or at The Postal Store® website at usps.com/shop. They must affix the stamps to envelopes of their choice, address the envelopes (to themselves or others), and place them in a larger envelope addressed to:
FDOI – Missouri Statehood Stamp
USPS Stamp Fulfillment Services
8300 NE Underground Drive, Suite 300
Kansas City, MO 64144-9900
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. There is a 5-cent charge for each additional postmark over 50. All orders must be postmarked by December 10, 2021.
Technical Specifications:
Issue: Missouri Statehood Stamp
Item Number: 481100
Denomination & Type of Issue: First-Class Mail Forever
Format: Pane of 20 (1 design)
Series: Statehood
Issue Date & City: August 10, 2021, Jefferson City, MO 65101
Art Director: Greg Breeding, Charlottesville, VA
Designer: Greg Breeding, Charlottesville, VA
Existing Photo: Charles Gurche
Modeler: Sandra Lane / Michelle Finn
Manufacturing Process: Offset, Microprint
Printer: Banknote Corporation of America
Press Type: Gallus RCS
Stamps per Pane: 20
Print Quantity: 18,000,000 stamps
Paper Type: Phosphor, Block Tag
Adhesive Type: Pressure-sensitive
Colors: Black, Cyan, Magenta, Yellow
Stamp Orientation: Horizontal
Image Area (w x h): 1.42 x 0.84 in. / 36.068 x 21.336 mm
Overall Size (w x h): 1.56 x 0.98 in. / 39.624 x 24.892 mm
Full Pane Size (w x h): 7.24 x 5.92 in. / 183.896 x 150.368 mm
Press Sheets Size (w x h): 11.84 x 21.72 in. / 300.736 X 551.688 mm
Plate Size: 120 stamps per revolution
Plate Number: “B” followed by four (4) single digits in all corners
Marginal Markings:
Front: Plate number in all corners
Back: ©2020 USPS • USPS logo • 2 barcodes (481100) • Plate position diagram (6) • Promotional text
Updated June 26th:
[press release]
Missouri Stamp to Honor State Bicentennial
WHAT: On Aug. 10, 1821, Missouri was admitted as the 24th state in the Union. In 2021, the U.S. Postal Service celebrates the state’s bicentennial with a new stamp.
The first-day-of-issue event for the Missouri Statehood Forever stamp is free and open to the public. News of the stamp is being shared with the hashtags #MissouriStatehood, #MissouriStatehoodStamp and #Statehoodstamps.
WHO: Peter Pastre, vice president, Government Relations and Public Policy, U.S. Postal Service, will serve as dedicating official.
WHEN: Tuesday, Aug. 10, 2021, at 9 a.m. CDT
WHERE: Missouri State Capitol
201 W Capitol Ave.
Jefferson City, MO 65101
RSVP: Dedication ceremony attendees are encouraged to RSVP at: usps.com/missouristatehood
BACKGROUND: The westernmost state when it entered the Union in 1821, Missouri was a natural resting place for settlers before continuing their journey to claim lands acquired in the Louisiana Purchase of 1803.
With 91 state parks and historical sites and hundreds of conservation areas, Missouri has an abundance of places to enjoy hiking, camping, fishing and other activities. It boasts world-renowned public gardens, world-class museums, several National Historic Trails, and professional sports teams including baseball, football, soccer and ice hockey.
Missouri is home to great food and great music. Some of the country’s best blues music is performed in concerts and clubs across the state. Whether it is Kansas City or St. Louis-style, Missouri is famous for its barbecue.
The people of Missouri are said to be stalwart and noncredulous, unswayed by eloquent speeches and unconvinced without adequate evidence, hence the state nickname: The Show-Me State.
From the USPS: The long-running series celebrating American lighthouses continues with five new stamps. The mid-Atlantic lighthouses featured in this issuance are: Thomas Point Shoal, MD; Montauk Point, NY; Harbor of Refuge, DE; Navesink, NJ; and Erie Harbor Pierhead, PA. The late Howard Koslow 
From the USPS: The U.S. Postal Service celebrates the enduring legacy of Western wear with four fun new Forever stamps in a booklet of 20. The stamp art features four graphic illustrations of Western wear staples — a cowboy hat, a cowboy boot with a spur, a Western shirt, and a belt buckle featuring a longhorn head. Each image is framed by elements common to the American West and iconography of the region, including cacti, snakes, roses and stars. Art director Greg Breeding designed the stamps with original art by Ryan Feerer.
From the USPS: With this commemorative stamp, the Postal Service recognizes the contributions of Japanese American soldiers, some 33,000 altogether, who served in the U.S. Army during World War II. The stamp, printed in the intaglio method, is based on a photograph. “Go for Broke” was the motto of the all-Japanese American 100th Infantry Battalion/442nd Regimental Combat Team and came to represent all Japanese American units formed during World War II. The stamp was designed by art director Antonio Alcalá.
From the USPS: Merging traditional artwork with modern design touches, this stamp depicts one of many stories about Raven, a figure of great significance to the Indigenous peoples of the Northwest Coast. Among the cultures of the region, Raven plays an essential role in many traditional tales, including stories about the creation of the world. Inspired by the traditional story of Raven setting free the sun, the moon and the stars, Tlingit/Athabascan artist Rico Worl depicts Raven just as he escapes from his human family and begins to transform back into his bird form. Antonio Alcalá served as art director.
From the USPS: These stamps pay tribute to heritage breeds, preindustrial farm animals that are enjoying renewed attention for their versatility, adaptability and unique genetic traits. This pane of 20 stamps includes photographs of 10 heritage breeds: the American Mammoth Jackstock donkey, the Narragansett turkey, the Cayuga duck, the San Clemente Island goat, the Mulefoot hog, the Cotton Patch goose, the American Cream draft horse, the Barbados Blackbelly sheep, the Milking Devon cow and the Wyandotte chicken. Zack Bryant designed the stamps with photographs by Aliza Eliazarov. Greg Breeding served as art director.
Just a guess: The Accocreek Post Office may not have the staff or experience to handle a first-day.
From the USPS: The Postal Service features a brush rabbit (Sylvilagus bachmani) on this beautiful new additional-ounce stamp, available on a pane of 20 or in a coil of 100. The pencil-and-watercolor illustration is from preexisting artwork by designer and illustrator Dugald Stermer. The brush rabbit is a small brownish cottontail rabbit of the U.S. West Coast and Baja California, Mexico. Art director Ethel Kessler designed the stamp.
Brush Rabbit stamp (Non-denominated Additional Ounce Rate) in one design, in a pressure-sensitive adhesive (PSA) pane of 20 stamps (Item 121100) and a PSA coil of 100 stamps (Item 740300). This stamp will go on sale nationwide January 24, 2021, and must not be sold or canceled before the first-day-of-issue.
From the USPS: In recent decades, Day of the Dead has caught on in the United States as a festive and increasingly popular celebration for all ages. These new stamps will be the first issued by the U.S. Postal Service to mark this holiday. Luis Fitch designed and illustrated the stamps. Antonio Alcalá was the art director.
From the USPS: These stamps capture many of the games Americans play for outdoor fun. A pane of 16 stamps features eight unique designs including: badminton, bocce, cornhole, croquet, flying disc, horseshoes, tetherball and a variation on pick-up baseball. Greg Breeding was the art director. Mike Ryan designed the stamps with original artwork by Mick Wiggins.
From the USPS: Four new postcard stamps celebrate the beauty and history of American barns. With differing qualities of light and color, each piece reflects one of the four seasons: a round barn surrounded by the hazy light and warm colors of fall, a gambrel-roofed barn in summer, a forebay barn in an early spring countryside, and a Western barn on a winter’s night. Ashley Walton designed the stamps with original artwork by Kim Johnson. Greg Breeding was the art director.
created digital paintings of four types of iconic barns found in the rural American landscape. With differing qualities of light and color, each piece reflects one of the four seasons:
