The 19th century was the Wild West of the United States Postal Service. Before standardization, the era was defined by rapid expansion, experimental printing methods, provisional issues, and structural flaws. Today, these historical anomalies translate into millions of dollars for sharp-eyed collectors.
Identifying a rare 19th-century US stamp requires transitioning from a casual hobbyist to a forensic investigator. This guide breaks down the precise, technical methodology needed to identify these elusive treasures, focusing on production varieties, grills, paper types, and watermarks.
1. The Anatomy of 19th-Century US Stamp Production
To spot a rarity, you must first understand the industrial landscape of the 1800s. Stamps were printed by private banknotes companies (Rawdon, Wright, Hatch & Edson; Toppan, Carpenter, Casilear & Co.; National Bank Note Co.; Continental Bank Note Co.; and American Bank Note Co.). Each left distinct physical signatures.
The Printing Process Matrix
- Line Engraving (Intaglio): The primary method used. Ink settled into recessed lines of a metal plate. Under a magnifying glass, genuine 19th-century stamps exhibit raised ink ridges that you can actually feel with a highly sensitive touch or see under angled lighting.
- Plate Varieties: Because plates were entered manually using a transfer roll, shifts, double transfers, and layout lines occurred frequently. A double transfer means the image was rocked into the plate twice, creating doubled lines in the lettering or frame.
2. Deciphering the “Grill” Varieties (1867–1871)
In the late 1860s, the Post Office faced a financial crisis: people were washing off cancellation ink and reusing stamps. To prevent this, the National Bank Note Company introduced grilling—pressing a patterned lead roller into the paper to break its fibers, allowing cancellation ink to sink deeply into the paper.
Grills are the holy grail of US philately. The world-famous 1¢ Z Grill (Scott #85A) is rare entirely because of its specific grill pattern.
How to Identify and Measure Grills
Grills are classified by letters (A, B, C, D, Z, E, F, G, H, I, J). To identify them, you must measure the physical dimensions of the grilled area and count the number of points (vertical vs. horizontal).
Grill Type Approx. Size (mm) Points (W x H) Key Rarity Example
-------------------------------------------------------------------------
Z Grill 11 x 14 mm 13 to 14 x 18 1867 1¢ Blue (Scott 85A)
D Grill 12 x 14 mm 15 x 17 to 18 1867 10¢ Green (Scott 85)
E Grill 11 x 13 mm 14 x 15 to 17 Regular production issues
F Grill 9 x 13 mm 11 to 12 x 15 to 17 Common on 1868 issues
- The “Points Up” vs. “Points Down” Test: Early grills (A, B, C, D, and Z) were impressed from the back, pressing the paper points upward toward the face. Later grills (E, F, G, H) pressed the points downward.
- The Foil/Pencil Technique: If a grill is faint, place a piece of high-grade aluminum foil over the back of the stamp and gently rub it with a soft eraser or cotton swab. The grill pattern will reflect clearly in the foil.
3. The Great Bank Note Company Shift (1870–1889)
The most common trap for collectors is distinguishing between the National (1870-1873), Continental (1873-1879), and American (1879-1889) Bank Note Company printings. They used the same basic designs, but their market values differ by thousands of dollars.
The Continental Secret Marks
When the Continental Bank Note Co. took over the printing contracts from National in 1873, they secretly altered the printing plates of the 1¢ through 15¢ values to distinguish their work. Learning these secret marks is crucial for accurate identification:
- 1¢ Franklin: A small crescent-shaped dash was added to the ball to the left of the numeral “1”.
- 2¢ Jackson: A small diagonal line was added under the scroll to the left of the word “U.S.”
- 3¢ Washington: A heavy, dark shading line was added inside the lower fork of the ribbon right below the word “THREE”.
- 10¢ Jefferson: A small semi-circular mark was added in the scroll immediately to the right of the numeral “10” on the right side.
The American Bank Note Co. Paper Pivot
In 1879, the American Bank Note Company absorbed Continental. They stopped using the hard, crisp paper of their predecessors and adopted soft porous paper.
- The Light Test: Hold the stamp up to a strong, focused light source. Hard paper looks uniform, dense, and translucent. Soft porous paper looks mottled, fibrous, and resembles a fine mesh or honeycomb structure when backlit.
4. The 1847 and 1851 Classics: Identifying First Issues
The first US general issue stamps were the 5¢ Franklin (Scott #1) and the 10¢ Washington (Scott #2) issued in 1847.
Spotting Counterfeits and Reproductions
Because of their high value, these stamps are frequently faked or confused with the 1875 official government reproductions (Scott #3 and #4).
- The 1847 Originals: Printed on thin, bluish wove paper. The initials “R.W.H.& E.” are clearly visible at the bottom border of each stamp.
- The 1875 Reproductions: Printed on crisp, thick white paper. The initials at the bottom are often faint or blurred because they were printed from entirely new, re-engraved plates, not the originals.
The 1851 1¢ Franklin Plating Complexities
The 1851 1¢ Franklin (Imperforate, Scott #5 through #9) is one of the most structurally complex stamps in existence. The design had top and bottom ornamental scrolls and curls that had to be manually trimmed to fit onto the printing plates.
- Type I (Scott #5): The rarest type. The complete design is intact, showing the top and bottom ornaments and the complete scrolls at the bottom.
- Type II (Scott #7): The bottom ornaments are complete, but the top curls are partially trimmed or missing.
- Type III (Scott #8): The top and bottom lines of the frame are broken or missing entirely in the center.
5. Watermarks and Paper Variations (Late 1890s Transitions)
As the 19th century drew to a close, the Bureau of Engraving and Printing took over production (1894). They introduced double-lined watermarks to combat counterfeiting.
Detecting the USPS Watermark
The letters “U S P S” (United States Postal Service) were watermarked into the paper sheets. A single stamp might only show a fragment of a single letter, or even just part of a curve.
- Proper Use of Fluid: Place the stamp face down in a black philatelic tray. Drop a few drops of specialized, non-flammable watermark fluid (or high-purity heptane) onto the back. The watermark lines will temporarily darken against the black background before evaporating.
- Double-Lined vs. Single-Lined: 19th-century Bureau issues (1895–1910s) utilize a Double-Lined USPS watermark. If you encounter a stamp that looks like an 1894 issue but features a watermark, its identity shifts entirely within the Scott Catalogue hierarchy.
6. Verification Checklist for High-Value Claims
If you believe you have discovered a rare 19th-century variety, you must eliminate mechanical manipulation before seeking professional certification.
- Check for Re-perforation: Fraudsters often cut off cheap perforations to make a stamp look like a rare imperforate variety, or add fake perforations to straight-edged stamps. Check the alignment using a precision electronic perforation gauge. Genuine perforations show natural, rough paper fibers inside the holes under magnification.
- Examine for Altered Color (Chemical Drifting): Exposure to sunlight, chemicals, or sulfur fumes can alter stamp colors (e.g., turning a common orange stamp into a seemingly rare brown variant). Examine the fibers on the back; if the paper itself is stained or discolored, the ink color has likely been chemically altered.
- Identify Regumming: A rare stamp with original gum (OG) commands a premium. Check if the gum looks suspiciously thick, uneven, or runs over the edges into the perforation tips—telltale signs of modern regumming designed to deceive.
Expert Protocol: Never clean or wash a suspected rare 19th-century stamp in water. Fugitive inks used during this period, particularly certain purples, blues, and reds, will bleed instantly, destroying both the stamp and its financial value. Always secure a certificate from recognized bodies like the Philatelic Foundation (PF) or Professional Stamp Experts (PSE) to validate your findings.
