Alt-country has always had some peculiarities associated with it. Is it country? No, not really. Then what the heck is it supposed to be? The broader term that easily encapsulates the "genre" as it stands is Americana. Moreover based in "roots-rock," and I use the term liberally, Americana strives to describe the rustic life. So what are its roots?
Alt-country as a genre can be classified as a subgenre or offshoot of Americana, but let's take the broader look at Americana and its evolution. The essential argument that could be made is that Americana was born with Gram Parsons. Begin with the Byrds's Sweetheart of the Rodeo. That album is typically considered to be the first in the genre. If the Byrds didn't hire Gram Parsons, who basically steered the ship in that direction (away from Roger McGuinn's planned jazz-psychadelia-rock-pop fusion hybrid first hinted at with the Notorious Byrd Brothers), then this album would have never happened. This record is watershed for two reasons: A. it's not psychadelic, as was the current trend, and B. because it based itself heavily in folk, with a total of seven folk songs (out of a grand total of eleven tracks). This album is probably the easiest to pinpoint as a root of Americana.
Tracing afterwards the path of Gram Parsons shows what he was essentially gunning for the whole time, his whole entire goal of the "cosmic American sound," as he put it. Listen to the Gilded Palace of Sin, by the Flying Burrito Brothers, and it's a mish-mash of folk influences, searing pedal steel (provided by the absolutely brillian "Sneaky" Pete Kleinow), as well as developing its own sense of a rollicking good time. Continue along and you find these influences well-developed on his solo efforts, GP and Grievous Angel. But after that, Americana seriously dropped off the radar.
The other possible root of Americana that must be discussed is the Band (as per usual). Music From Big Pink and the Band both serve as case studies of the genre. The love for storytelling, the appropriation of rustic themes have long served as springboards for the Americana movement. And the distinction that the Band carries is that their music was somehow timeless and boundless, because you could figure it could from anywhere, from anytime. The "Gram Parsons Americana thread" can be considered dated in the sense that it sounds like it comes from a time period; the Band have no such issue at hand. Play the Band for someone unfamiliar and see if they can pinpoint it to a particular time period or a particular place. They probably won't get both. I've already given a lot of manlove for the Band, so I'll avoid that here, but it is important to note what they did for the genre (and for rock music and general).
So fast forward to the 1990s. In the midst of 80s pop and all its glamour and extravagance, America (especially Middle America, i.e. the Midwest) was, for the most part, left out of it. Same old life, same old town. This scenario is where "alt-country" was born. The most obvious root of this genre was a band by the name of Uncle Tupelo.
Based largely in Illinois, Uncle Tupelo originally channeled the sort of suburban/rustic discontent associated with the Midwest, primarily through a particularly strange fusion of folk and punk (also regarded as "cowpunk" by some). This is evident on their first record, where only a couple of folk songs appear as mere stopgaps between the fiery blasts of punk. But, for whatever reason, Uncle Tupelo mellowed out and made the defining album of the alt-country movement, Anodyne. Though from there they split up into the resulting entities of Son Volt and Wilco (commence common bickering of who's better and etc.?), the mark they left on the genre is indelible. Without a doubt, Uncle Tupelo created the alt-country genre. Their first album even spawned the genre's flaghsip "magazine, " No Depression. If you only had to listen to one alt-country artist, it would be defnitely be Uncle Tupelo, no exceptions.
The other commonly-referred champion of the alt-country genre is the Jayhawks. Largely based in Minnesota, they chose to more rather approach alt-country by taking the folk elements and filter it through a more "pop" (I hate to use this label, but I have not found anything better) lens. This makes for lighter listening compared to Uncle Tupelo. Hollywood Town Hall largely evinces their successful approach to the genre.
In some perverted way, the easiest way to determine the existence of some sort of genre is to assess the existence of any "supergroup," and by golly, there is one...Golden Smog. Featuring many of the titans of alt-country (i.e. Jeff Tweedy of Wilco/Uncle Tupelo, Gary Louris of the Jayhawks), they certainly hold their water in their efforts, consistently plumbing that "classic" alt-country sound (more akin to the Jayhawks line of work) into good songs and good records.
Since I have been in a list-making mood recently, I decided to compile a sort of top albums in alt-country. This means that I'm purposefully excluding the broader Americana genre. Without any further ado:
1. Uncle Tupelo - Anodyne
As I stated earlier, this is simply the greatest alt-country record around. Purposefully constructed, it presents all sides of the genre. But the greater achievement is that though it displays many sides of the genre, it sounds greatly holistic...always alluding to a greater sound. That was the only discernible weakness of Uncle Tupelo's previous efforts. More often than not, there were only two types of Uncle Tupelo songs: the raucous punk songs and the obviously softer folk numbers. It wasn't really until after that where the band managed to unify those disparate elements into one sound, from the rollicking romp of "Chickamauga" to the easier sitting "New Madrid" that Uncle Tupelo became truly great. While entirely different, those two styles seem to be cut from the same cloth. While Jay and Jeff couldn't have been farther apart, they couldn't have sounded more similar.
2. Son Volt - Trace
And so we essentially solve the "who is the more alt-country?" out of the pair. Trace also serves as a quintessential alt-country album. Jay Farrar had never written better (and arguably since) this record: the typical themes of road and essentially rural existence are never overused and overwrought. The sound that Jay whetted during his Tupelo days are here in full force...and the results from combining his writing and his songs are quite serendipitous. The case in point is the opener, "Windfall." You could argue that Jay has never written anything quite has good since. You can also argue it took Jeff Tweedy (forever pitted against each other, though unwillingly) a whole lot of time to ever write at that level. But that's how it panned out. Can't complain, though...how could you?
3. The Jayhawks - Hollywood Town Hall
And the "other" alt-country band. I suppose that's a dubious title, but let's not kid ourselves, this is a good record. Like, really good. While the aethestic recalls the music of yesteryear, the filter its cast through makes this a perfect alt-country record also. It hints at the timeless Americana that the Band achieved, but considerably more modern (and so not so timeless).
Gary Louris and co. work together full-time to provide a consistently warm existence that makes this album an easy selection for this list.
4. Uncle Tupelo - March 16-20, 1992
Now I really normally don't like to put two of the same artist in any list, but as is obvious, the list of good alt-country artists (and good alt-country albums) is, well, pretty short. But I violate my cardinal rule moreover because of the record's significance. The most obvious comparison is that this is alt-country's Sweetheart of the Rodeo. Whereas Sweetheart of the Rodeo combatted the rampant psychadelia of the time, March 16-20, 1992 combatted the rampant Nirvana-ness that pervaded popular music. It was a masterstroke, both to affirm their folk/Americana roots and to out-punk and to out-sleuth the rest of the music world (the rumor is that this record led to MTV's Unplugged series). To go the straight opposite way was brilliant. Consistingly primarily of old folk tunes, Uncle Tupelo showed great maturity and essentially showed that they were ready to integrate the diametrically opposed punk and folk parts of their existence.
5. The Bottle Rockets - The Brooklyn Side
The Bottle Rockets are technically an offshoot of Uncle Tupelo: Brian Henneman was a swingman for Uncle Tupelo, but later split off (earlier than the actual breakup) to form the Bottle Rockets. To sum the band up quite simply, they channel alt-country through a sort of Creedence Clearwater Revival swamprock meets Lynryd Skynyrd sort of deal. It's rollicking good fun. The guitars are smoking, the music rousing...it sets the stage. Therefore, it's simple to rank them here by just picking their best effort.
The cream of the crop is thin, and so we stop here, leaving the records that went beyond alt-country (i.e. Wilco's Being There and the Jayhawks's Tomorrow the Green Grass) and the almost-haves (i.e. Ryan Adams in general).