After a small trove of these cards came my way, and I found some decent information on some of the others, I decided to make a page for just Minnesota, including Carnegie buildings and regular library buildings alike.
There were 65 Carnegie buildings. I like to think this results from that Upper Midwest mixture of Lutheran socialism and Scandinavian frugality.
1901 Carnegie Library.
The older card has a postmark too blurred to yield a date.
The older card (L) dates from soon after construction. The
landscaping of the newer card (R) looks to be about 3-5 years
advanced.
Two cards illustrate why you can't rely on linen finish cards for a totally accurate picture of a building. Still, it's a pretty good example of Prairie style.
1911 Carnegie building. Currently a branch of Lake Agassiz Regional Library.
Minnesota State Historical Society's description concurs. I wish that their photo gallery was a little more extensive. The city website at least gives a current picture.
Two beautiful pre-WWI postcards. Neither was postally used: both have divided backs.
A rather pretty building (3 grants dating since 1899) with some stylistic quirks, such as a tile roof coupled with Federal building details, including that dome.
(R) 1910 or 1911 Curt Teich 'American Art' card printed for the Duluth Photo Engraving Company. Unusually for a Curt Teich product, photo credit is given (Mc Kinzie).
Currently, the building appears to be owned by a management firm whose stated goal is to restore the building. I have no independent confirmation of this.
The new building is rather scary looking. It has a Rorschach quality: I see an aerial hockey rink. Perhaps you see a ship's prow.
1911 Carnegie grant. Still in use. The Hockey Hall of Fame gets a much more prominent place on the city's website.

(L) This V.O. Hammon card is of rather mediocre quality overall, but someone there had a talent at making retouched leaves look real.
(R) The public library (1901 grant) is in the upper left corner of the card. This link will take you to a picture on the opposite end of the size spectrum.

Improbable color scheme on this early (mailed 1907) Curt Teich card (unevenly divided back).
Replaced by the Marshall-Lyon County Library: current fate of the 1903 building is unknown.

Currently part of Lake Agassiz Regional Library.
1906 Carnegie grant. Replaced by a building that looks as if it was built in the late 1950s.

1903 grant: opened 1904.
Great googly-moogly, what a Carnegie building! Looks like the Pipestonians
have been very ambivalent about their
library,
moving it into the school library, and transferring this building to
the Pipestone Senior Center.
The combined collection is the Meinders Community Library.

1901 Carnegie grant.
Now part of the Great River Regional Library system. The building was replaced in 1979, but whether it has been demolished is another question.
Card was postmarked 1910, but has no statement of responsibility visible.

Replaced, possibly due to 1998 tornado damage.
1903 Carnegie grant. The building (architects R.D. Church and Ole Fredrickson)
is somewhat similar
in plan to the Des Plaines, Illinois Carnegie building. It was added to the
National Register in 1983.
The card is of the Bloom Bros. Quality Line, but also has 'Gilbert' worked into the divider on the reverse.

1902 Carnegie building renovated in 2006 . It spent the construction year in a local mall. From its web site, it looks as if everything went well. Good thing it was finished before the economy bottomed out.
1903 Carnegie grant; card postmarked 1916.

I assume that the library is the left building, and that the flag is in front of the post office.
Curt Teich 'C.T. American Art' postcard, mailed 1938.
Deco replacement for the Carnegie building, on a Real Photo Postcard.
In use 1889 - 1961.
Not intended to be a loafing place for tramps to read dime novels.
--Thomas Hale Williams, about the Athenaeum (1877), quoted in
Minneapolis Observer Quarterly.
Full (and funny) history on the
Minneapolis Observer site,
who in turn cited The Library Book:
Centennial History of the Minneapolis Public Library,
by Bruce Weir Benidt (1984),
Minneapolis Public Library and Information Center: Minneapolis.
No, those are not solar panels on the left-hand picture. Minnesota wasn't that progressive in 1907.
Now incorporated into the renowned Hennepin County Library System.
(L) From the reverse of the Plastichrome card by Colourpicture Publishers of Boston 30, Mass.:
This magnificent gold trimmed Public Library, serving as headquarters for Hennepin County and Minneapolis libraries, is located in the Gateway Development Area, 300 Nicollet Avenue. The structure is made of granite, Italian marble and anodized aluminum. The library, geared for the comfort of its visitors, features smoking lounges and open shelves, invites browsing and casual research. The library also features a planetarium where regular shows are presented.
(R) From the reverse of the Mirro-Krome card by H.S Crocker, of Minneapolis 23, Minn.:
The new gold and granite Minneapolis Public Library, headquarters for both Minneapolis and Hennepin County Libraries, is located in the Gateway Development Area, 300 Nicollet Avenue.
Vivid colors, light and space combine with glass, Italian marble, teakwood and anodyzed aluminum in this modern library. Smoking lounges and open shelves invite the visitor to browse and wander.
A blacklight hall of time and space and a planetarium, where regular shows are given, are unique features of the library.
Still in use, with a branch - Blooming Prairie Branch Library.
The library situation of this city is rather hard to fathom. Their web site is not helping me.

Post-1907 card mailed 1911. This building clearly dates from prior to the turn of the century. Since much of the city was destroyed by a tornado in 1883, I'd presume
the building is newer. However, it looks like it could have withstood a F3 or so.
The maple trees appear to be 2 - 3 years old.

Bloom Bros. Co. 'Scenic America' postcard with evenly divided back. The trees are
slightly larger than in the first picture. The mens' fashions look to be
from the 1910s.
This was the first card of the bunch that I purchased. I needed the one
above to tell the YMCA from the library.
The RPPC is clearly from the forties, whereas the linen finish card appears to date from the 1930s. It was mailed in 1948. The limestone building closely resembles that of 1930s Highland Park, IL.
The picture on the library website is definitely not that of this building. It appears to
date from the 1950s or 1960s. They sure replace things fast up there!

Probably part of the hospital complex, but whether as a medical library, or as a service to patients, I do not know. It really looks like a Georgian public library.
The gardens are well-tended, which would be good therapy for either gardener or visitor.
Built during the Great War.
Unlike Minneapolis, St. Paul seems to replace
libraries
only when absolutely necessary. Looks like a 1915 fire was the only good enough reason.
Card caption:
New Saint Paul Public Library and the L.J. Hill Reference Library, Saint Paul, Minn.
I'd like to think my great-great-grandfather spent his last years enjoying this building.

Built in 1899.
It may look like a Carnegie library, but it's not. The card, with an unevenly divided back, was mailed in 1911.
Still in use. It's on the National Register of Historic Places. Look near the bottom of the linked page.
Drop that mouse and visit your public library.
(Or, if you're viewing this in the library,
set the mouse down carefully.) All the following resources were found at a local
library.
Bial, Raymond and Linda LaPuma. 1991. The Carnegie Library in Illinois.
(With Photography
by Raymond Bial.)
Bobinski, George S. 1969. Carnegie Libraries: Their History and Impact
on American Public Library Development.
Dickson, Paul. 1986. The Library in America: A Celebration in Words and Pictures.
Frye, Lonn. 1992. Carnegie Libraries: Restoration and Expansion.
Krass, Peter. 2002. Carnegie.
Van Slyck, Abigail. 1995. Free to All: Carnegie Libraries and the American Culture,
1890-1920.
© 2007 - 9 Judy Aulik
Uploaded 17 August 2007.
Updated 15 July 2009.