他以列兵身份参加了墨西哥战争。

He enlisted as a private in the Mexican War.

《柯林斯英汉双解大词典》

如果这场战争能胜利，也许墨西哥商人可以开始相信他们的国家比他的南面的对手变得更加有竞争力和强大。

If this battle is won, perhaps Mexican business people can start believing that their country has what it takes to become more competitive and powerful than its big rival down south.

youdao

后来波尔克这样写到：“我们并不是为了征服而战争，而是为了我们尽可能以和平方式从墨西哥获得加利福尼亚和其他地方不得已而为之。”

Later, Polk wrote: "we had not gone to war for conquest. But it was clear that in making peace we would, if possible, get California and other parts of Mexico."

youdao

We only usually bring it up when we're talking about the Mexican War and its aftermath, or something.

我们通常只会在谈论,类似墨西哥战争及其影响时,才会谈到它

耶鲁公开课 - 美国内战与重建课程节选

Or was it 1840? Or was it really in the wake of the Mexican War when you get this massive expansion into the great southwest and the Mexican Session which we'll take up actually next week?

还是1840年,在墨西哥战争的前夕,美国大举扩张进入,广阔的西南部地区及墨西哥会议的召开,这些其实我们下周都会讲到

耶鲁公开课 - 美国内战与重建课程节选