Baltimore Md., 1c Red on Bluish
(1LB1). Type 3, left sheet margin, other sides large to just touching
at top, tied by black grid on Mar. 3, 1853 folded letter to local
addressee, Very Fine and choice (Image) 
Baltimore Md., 1c Blue
(1LB3). Type 7, huge margins including left sheet margin, tied by pen
strokes on blue cover to local street address, bookseller's handstamped
corner card, Extremely Fine, a remarkably choice cover, ex Waterhouse (Image) 
Baltimore Md., 1c Green
(1LB4). Type 5, pencil cancel has been lightened for cosmetic effect,
used with 1c Blue, Ty. II (7), large margins to slightly in, top of
stamp affected by insect nibbling, both stamps tied by blue
"Baltimore Md. Feb. 24" circular datestamp on brown cover to local street
address, a few spots in cover eaten thru by mildew or insects, repaired
corner at bottom right, could easily be restored to Very Fine
appearanceTHE ONLY RECORDED COMBINATION OF THE ONE-CENT 1851 ISSUE AND THE RARE BALTIMORE GREEN CARRIER STAMP. AN OUTSTANDING USAGE.
A quirk of the postal regulations created the potential for a drop-letter and carrier-fee combination. If a letter were deposited at the post office ("drop letter") and delivered to the addressee by a carrier, both the 1c drop rate and 1c carrier fee would apply. However, if the letter were given to the carrier department, which was an entity separate from the post office, the drop rate did not apply, and the intra-city 1c carrier fee would be sufficient to have the letter delivered to the addressee by the carrier department. It is obvious that the cheaper method was used more often. In this rare instance, the sender used a 1c regular stamp, prepaying the drop-letter rate, and affixed a 1c carrier (in this case, the rare Green 1LB4 stamp). This is the only recorded example of this combination, the cover offered in the following lot has a trimmed 1c 1857.
Ex Ackerman. (Image)
Baltimore Md., 1c Green
(1LB4). Type 4, margins clear to touching, tied by pencil, used with
1c Blue, Ty. V (24), perfs trimmed but design has Type V
characteristics, tied by blue "Baltimore Md. Sep. 20" circular datestamp on
buff cover to local addressee, creased away from stamps, Fine, extremely
rare combination of carrier fee and drop rate
(Image) 
Baltimore Md., 1c Green
(1LB4). Type 9, bottom sheet margin, other sides large to clear, deep
shade, tied by two pen lines, used with 3c Brownish Carmine (11), large
margins, tied by blue "Baltimore Md. Dec. 17" circular datestamp on 1852
blue folded letter to New York City street addressEXTREMELY FINE. ONE OF THE FEW GENUINE COVERS KNOWN WITH THE BALTIMORE GREEN CARRIER STAMP USED WITH THE 3-CENT 1851 ISSUE. THIS IS ARGUABLY THE FINEST OF ALL 1LB4 COVERS.
Ex Caspary (where acquired by the Halls). (Image)
Baltimore Md., 1c Green
(1LB4). Type 3, huge margins including left sheet margin, cancelled by
pencil on lady's embossed cover to "Mr. Barret" with carrier's
pencil street notation "Eutaw" at lower left, with matching embossed
letter enclosure, a lady's acceptance of Mr. Barret's
invitationEXTREMELY FINE STAMP AND IMMACULATE COVER. THE BALTIMORE GREEN CARRIER STAMP IS AMONG THE RAREST OF SEMI-OFFICIAL ISSUES.
Acquired by the Halls in the Harmer, Rooke Oct. 26, 1949, sale. (Image)
Baltimore Md., 1c Red
(1LB5). Type 5, large margins, rich color, tied by black "1" in
circle on folded cover to local addressee, file fold clear of stamp,
but the stamp has two long tears that are evident with close examination,
Very Fine appearance, the Red on White stamp is extremely rare on cover --
rarer, in fact, than the Green, ex Ackerman
(Image)