Noted by Cal Hahn as earliest reported receipt for a valuable letter is this one which reads:

"Marshall Post Office Dec. 1, 1840
I do hereby Certify that Messrs. Gorham & Brown have this day deposited in this Office to Mail a letter addressed Higginson & Clapp of New York Containing Two hundred dollars in bills of different banks. Chas. D Smith P.M."

This note signed by the postmaster attested to the fact a patron deposited into the mails a letter containing two hundred dollars, several years before Registered Mail was adopted.

In the Postmaster General's Report of November 17, 1828, Mclean wrote that "It may be advantageous to the public and the department at some future time, for it to become the insurer of moneys transmitted in the mail, being authorized to charge a higher rate of postage in such cases to indemnify for the risk incurred. To guard against frauds, this responsibility must necessarily be limited to packets mailed at principal offices, under such regulations as shall afford the greatest possible security"

Red Reading, PA Sep 5 cds and red "5" on 1848 cover to Pittsburg with manuscript "R" of the Reading "recorded" plan.

In the mid-1800s, concerns over the loss of valuable mail prompted the Post Office Department to introduce an official registration system on July 1, 1855, for a fee of five cents.

However, in the decade prior, an unofficial system for registering valuable letters was adopted at the Philadelphia post office from 1845 - 1854. The unofficial registration system spread from Philadelphia to other post offices throughout the country. Postmasters played a key role in this process, marking valuable letters with an "R" handstamp and recording their details. Although no fee was charged, these letters were tracked and handled with greater care.

This cover is an example of a manuscript "R" notation.

Black Mercer Dec 20, Pa and clear strike of matching "10" on folded cover to Philadelphia, with 1849 lettter enclosed. Small blue Philadelphia "R" (Type 2)

Black Apr 28 Muncy, Va cds with black straightline "PAID" and "5" in circle handstamps. Large blue partial "R" handstamp on 1848 folded letter to Philadelphia.

Scarce, small red "R", Type 6. Jun 16, 1856 on cover to Philadelphia

Red Sep 11 Bloomsburg, PA with matching "5" in circle handstamp. Large blue "R" on 1849 folded letter to Philadelphia.

Blue Nov 13, Baltimore, Md 1849-50 cds with blue "PAID" and dark blue small "R" (Type 2). Addressed to Philadelphia.

Blue Sep 16 Baltimore, Md cds with dark blue small "R" (Type 2) and red straightline "PAID", addressed to Philadelphia.

Red Ballston Spa, NY Apr 26 with matching small "5" handstamp on 1849 folded letter to Philadelphia. Two blue strikes of the Philadelphia "R"

Type I Large Blue "R" Philadelphia marking with large negative "5" handstamp. Blue Feb 22 Trenton, N.J. cds. On Folded letter to Philadelphia.

Black Jul 11 New-York 5 Cts. cds of 1851 (known perfect for 5 weeks only) and large, light blue Philadelphia "R" (Type 3)on letter to Philadelphia.

Red Boston Sep 21, Mass cds with matching straightline "paid" and manuscript "20" in pencil. It is also marked with a black "20" similar to the one on cross-border mail. It has a small blue Philadelphia "R" and a manuscript "45", likely the recording number.

Red Boston Sep 21, Mass cds with matching straightline "paid" and manuscript "20" in pencil. It is also marked with a red "20."

Red Boston MAY 23, Mass cds with matching straightline "paid" and manuscript "20" in pencil. It is also marked with a red "20."

Red Mar 6 Reading, PA and red "5"on 1849 folded coverwith Reading manuscript "Reg" and large blue Philadelphia "R"

Type I Large Blue "R" Philadelphia marking with manuscript "20" on folded letter to Philadelphia. Oct 1 Pittsburgh, PA cds. 30 Sept 1846 docketing.

Red Feb 20 Reading, Pa cds with red "5" and Large blue Philadelphia "R" on folded cover to Philadelphia.

Lancaster Pa. Jul. 13 (1851) red circular datestamp struck partly off cover at top, matching "5" rate handstamp and manuscript "R" for registered, manuscript "7" control no. at left, small piece of backflap missing.

Blue Nov 20 Danville, Pa and circled "PAID 3" with manuscript "Reg" and "9" for registered. Small red Philadelphia "R"

Blue Dec 17 Cincinnati cds on cover to Illinois. Large red Cinncinati "R" and straightline "PAID" with manuscript "Paid, & Registered"