What do the following sentences from "A snapshot at the President" by O. Henry mean?

I am guessing they got the brother to co-sign a note.

The "a slight draught" is beyond me. Sight draft would make somewhat more sense.

I looked up my dictionary and found that draught sometimes equals draft. In this sense, does this phrase mean we got a slight draft of 4000 dollars from Major Hutchinson. By the way, "Major Hutchinson" is the name of a place, isn't it?

Major Hutchinson is a person. Major is a military rank above Captain and below Lieutenant Colonel. He may or may not be a currently serving officer, since officers of the rank of Major and above (i.e. holding "field rank") may keep their rank as a courtesy title after they retire. (This is the situation in the British and British Commonwealth forces, I believe it is true in the US forces too)

You are aware, of course, that O. Henry is a humorist. His humor is of the wry
variety and not to all tastes, but I digress. Note that he says he obtained only
a twenty dollar loan even though he put up both his printing press and a cow.
If you'll forgive another digression, the magazine he was running was called
"The Rolling Stone". Hmmm . . . But to resume. Not only was he unable to get
more than $20.00, but in addition he had to put up his brother's name (i.e.
his reputation). Furthermore, he needed a draft (draught), that is, an order for
the withdrawal of money, on Major Hutchinson. I don't know who the Major was,
but apparently he was a source of money for "The Rolling Stone" and is referred
to as if he were a bank. The draft, which would secure a loan of twenty bucks,
was for a whopping four grand. That's a lot of money even now, but at the turn
of the century it was a small fortune.

So "The Rolling Stone" was considered such a bad risk that they had to put up
their printing press, a cow, and a promise of $4000.00 in order to get a $20.00
loan.

Hilarious, no?

He got better later in his career.

Why are you reading this, anyway?

Thank you for the background information! It is not always easy for a second language learner of English, such as me, to find a reliable source for names of places or people occurred in the article we are reading. Even though these names may not influence the understanding of the article that much, we do appreciate a better knowledge of it. Thank you, again!

I am trying to translate this short fiction into Chinese, since I am always crazy about the works of O. Henry. I am a postgraduate majoring in translation and doing this will also help me to become a qualified translator one day.
I just embarked on this endeavor and found that this is not an easy work. Many parts of this story, for example, are totally beyond me. Oh, my mother tongue is Chinese, and English is my second language. Thanks you so much for your detailed illustration, it is of great help. I may run into more problems in the future, and any comments or suggestions from you will be highly appreciated.
All the best!

As I recall from my days over there, Chinese dialects are not exactly "humor rich". As George implied you not only want to translate the words but O'Henry's more subtle meanings.

Thank you for your kind suggestion, I will try my best.
Great differences do exist between Chinese and English in terms of ways of expression, and it is the job of a translator to bridge whatever gap there may be. I believe that Chinese, as a language that has been constantly enriched over a long period of time, is rich enough to cover the subtlest meaning of whatever work.
Whenever it is that you came to China, I am sure that if you come once again, you will be impressed by the changes that will meet your eyes.
You are always welcome!