Free How Few Remain by Harry Turtledove

Territory and California have a lot longer stretch of border with ’em than Texas does, and the Yankees have a railroad down there, so they can ship in troops faster than we can hope to manage it. What are we going to do?”
    “Whatever it takes, and whatever we have to do,” Stuart said, though he recognized the answer as imperfectly satisfactory. “I’ll tell you this much, Major, and you can mark my words: once those provinces are in our hands, we
will
have a railroad through to the Pacific inside of five years. We aren’t like Maximilian’s pack of do-nothings down in Mexico City. When the Anglo-Saxon race sets its mind to do something, that thing gets done.”
    “Of course, sir.” Major Sellers was as smugly confident of the superiority of his own people as was Stuart. After a moment, he added, “We’ll need a railroad more than the greasers would have, too. We’ll use it for trade, the same as they would have done, but we’ll use it against the United States, too, and they never would have bothered with that.”
    Stuart nodded. “Can’t say you’re wrong there. If Mexico ever got into a brawl with the USA, first thing she’d do would be to pull out of that part of the country and see whether a Yankee army was still worth anything once it got done slogging its way through the desert.”
    “No, sir.” Sellers shook his head. “The first thing Maximilian would do would be to scream for us to help. The second thing he’d do would be to pull out of Sonora and Chihuahua.”
    “You’re likely to be right about that, too,” Stewart said. The sound of boots clumping on the dirt made him turn his head. An orderly was coming up, a telegram clenched in his right fist.“Well, well.” One of Stuart’s thick eyebrows rose. “What have we here?”
    “Wire for you, sir,” said the orderly, a youngster named Withers. “From Richmond.”
    “I hadn’t really expected them to wire me from Washington, D.C.,” Stuart answered. Major Sellers snorted. Withers looked blank; he didn’t get the joke. With a small mental sigh, Stuart read the telegram. That eyebrow climbed higher and higher as he did. “Well, well,” he said again.
    “Sir?” Sellers said.
    Stuart realized
well, well
was something less than informative. “We are ordered by General Jackson to assemble two regiments of cavalry and two batteries of artillery at Presidio, and also to assemble five regiments of cavalry, half a dozen batteries, and three regiments of infantry here at El Paso, the said concentrations to be completed no later than May 16.” The date amused him. Most officers would surely have chosen the fifteenth. But that was a Sunday, and Jackson had always been averse to doing anything not vitally necessary on the Sabbath.
    Sellers whistled softly. “It’s going to happen, then.”
    “I would say that appears very likely, Major,” Stuart agreed. “Presidio is on the road to the town of Chihuahua, the capital of Chihuahua province, which we would naturally have to occupy upon annexation. And of the larger force to be assembled here, I presume some will go to Hermosillo, the capital of Sonora province—which I suppose will become Sonora Territory—and some will defend El Paso against whatever moves the United States may make in response to our actions.”
    “We’ll have to post guards all along the railroad.” Now Major Sellers looked north. The Texas-New Mexico frontier and the Rio Grande pinched El Paso off at the end of a long, narrow neck of Confederate territory, through which the Texas Western Railroad necessarily ran. Small parties of raiders could do a lot of damage along that line.
    “Once the annexation goes through, we won’t have any trouble moving south of the Rio Grande. We’ll have more depth in which to operate,” Stuart said. That was true, but it wasn’t so useful as it might have been, and he knew as much. No railroad to El Paso ran through Chihuahua province; movement would have to be by horseback