Oh, oh, let's play the "find similar but older music" game!
I'll go next! You were on the right track with blues from Texas, but it goes way before 1949. Try to find the Chuck Berry riffs...
http://www.youtube.com/watch?v=odwaE1hlwgc
T-Bone Walker - I Got A Break Baby (1942) (B-side of Mean Old World, Capitol 10033) (Wikipedia: http://en.wikipedia.org/wiki/Mean_Old_World)
Here's an article about him that I grabbed off Wikipedia's sources: http://www.there1.com/browse_articles.php?action=view_record...
> "[This single was] the first important blues [recording] on the electric guitar"
Some other cool stuff in the article too, like how he worked with Blind Lemon Jefferson (Robert Johnson also worked with him) and with Charlie Christian, who brought the electric guitar to jazz.
I'll go again just because it's fun: https://www.youtube.com/watch?v=EbWmAgp2R30 - Ernest Tubb - Walking The Floor Over You (1941) (Wikipedia: http://en.wikipedia.org/wiki/Walking_the_Floor_Over_You)
A country single that sold over a million copies, and it used that nice prominent electric guitar, beating Walker by a year.
Reading further on Wikipedia to try and find earlier recordings, I'm pointed to an artist I've been exploring only this past week: Milton Brown & His Musical Brownies, one of the "big 3" Western Swing artists (along with Spade Cooley and Bob Wills & His Texas Playboys).
Ugh, this stuff's hard to find on Youtube... Found something: https://www.youtube.com/watch?v=qnjE5aB-cWQ - Milton Brown & His Musical Brownies - Right Or Wrong (1936, date source: http://www.secondhandsongs.com/performance/200653)
Note the electrified pedal steel solo midway through. That's some innovative stuff, though I like Merle Haggard's version better (on his Bob Wills tribute album, "A Tribute To The Best Damn Fiddle Player In The World" from 1970. Wills' version is also pretty good, but not all that much better than Brown's. As you can see, I think Western Swing is great stuff (my last.fm is utterly full of it), and my secret theory is that there were only 3 big Western Swing bands because there were only 3 pedal steel players talented enough in the 30s and 40s to do the style justice. Before it came along, there wasn't all that much popular music that really used the electric guitar.
Anyway, I digressed pretty hard, but I think I've made my point somewhere in there...