Much of America as we know it evolved in the 19th century, as we'll explore in a series of three conversations this week with writers who seek out new ways to understand old events.
It's easy to define the squiggly border between Mexico and Texas: It's determined by the Rio Grande river. But the rest of the U.S.-Mexico border is not so obvious — the straight lines are drawn seemingly at random across mountains and deserts.
In her book Line in the Sand, historian Rachel St. John traces that dividing line to its beginnings in the mid-1800s. "Part of what's interesting to me about the western border," St. John explains to NPR's Steve Inskeep, "is that there really is no there there, before the United States and Mexico sit down and decide that they're going to draw this line."
On how the U.S.-Mexico border came into existence as a product of the U.S. defeat of Mexico in the 1840s
"When the U.S. and Mexican governments [and] their peace negotiators, sit down to create the border, they mostly picked a few sort of geographically important points, a few points that they knew about — frankly because neither government knew very much about this territory at all. And then they drew a series of straight lines between them."
On the United States' mistakes and second thoughts
"It wasn't just that [the U.S.] didn't like where [the border] had been drawn, it's that they messed up, basically. What happened in the Peace Commission is that they wrote down a series of directions about where the border should be: It should start a marine league south of San Diego and run in a straight line to the Colorado River, there is a long series of descriptive explanations. ... They attached a map — the best map they had at the time of what this territory supposedly looked like. ...
"Well the problem is: when the boundary commission got into the field, it turns out that the map, it was in the wrong spot. So the boundary commissioners on the spot had to make a decision, they decided to compromise and give a little bit more land to Mexico in one way and little more to the U.S. in the other. And when this boundary came out, the U.S. Congress was not happy with it at all and it's partially that discomfort about where the boundary line lay that led to the renegotiation of the boundary line in the Gadsden Treaty just five years later.
On railroads and the Apaches
"There was a theory at the time that the best location for a railroad to go across the southern U.S. would be through southern New Mexico and through southern Arizona. The railroad does not end up going through there for a very long time.
"The other thing the U.S. did ... is that they promised to keep Indians, particularly Apaches, from raiding into Mexican territory and they said they would pay for any damages basically caused by Indian raiding.
"It only took five years for the United States to realize that was an impossible promise to keep. It's territory that's really controlled by Apaches at the time. When the U.S. boundary commissioners and the Mexican boundary commissioners get out into the field, they realized Apaches are raiding heavily throughout northern Mexico and there is, at that time, very little the U.S. Government can do to stop it. One of the things they do in the Gadsden Treaty then is they back down on that provision and they get Mexico to agree to basically let them off the hook for preventing raids."
On how the Apaches didn't care much about the abstract line drawn by Mexico and the U.S. ... but soon learned to use it to their advantage
"The Apaches realized that if they are in the United States and they are being chased by U.S. troops, the best way to get away is simply to cross the border because the U.S. troops can't cross into Mexican sovereign space. There's this sort of cultural cliche of making a run for the border to escape law enforcement: The Apaches are really the first people who learn how to do that and do it quite effectively."
On modern-day border debates
"When people talk about the politics of the border today, they often refer to a sort of imagined historical time in which particularly the U.S. government had control of the border. There's a lot of rhetoric of 'We have lost control of the border.' Studying the history of the border, I don't see a time when the United States ever had control. It's always a negotiation between governments trying to establish certain laws, people who want to evade those laws finding ways to do so, government coming back, smugglers responding in turn. There's always a sort of dance going along.
"The other thing I think that really stood out to me is that, like most Americans, I think I assumed going into this project that the border is primarily about immigration and in some ways I imagined that the purpose of borders is to control the movement of people. And in the 19th century that's just not the case at all. ... this is, I think, a 20th century phenomenon."
On the meaning the once-arbitrary border has developed over time
"When the boarder is first created ... there's this somewhat arbitrary line drawn ... and then the border becomes this important space that draws people to it. People actually go to the border and establish towns, setting up points of entry that monitor customs across the border. Then people decide to build businesses on the border in order to service the development of transporter trade."
On the idea of "If you draw it, they will come"
"One of the things that's interesting about the border is that initially when the boundary commissioners were originally drawing this line, many of them kept saying: This is a desert, no one's ever going to settle here. ...
"It's 1850, it's hard to move around in the desert, it was hot, over 110 degrees and they literally say, 'Look we're not going to do a full survey of this line because no one's ever going to live out here.' I often think if those people could come back now they'd be amazed to see places like Tijuana that they never could have imaged would develop."