How did Mr. Lincoln respond to Jethro's letter in chapter 9 of "Across Five Aprils"?

In chapter 9 of Irene Hunt's "Across Five Aprils," President Lincoln wrote to Jethro Creighton in response to a letter that Jethro had written to him concerning the men who had deserted their regiments.  Jethro was specifically trying to find help for his hometown friend, Eb.  Jethro had asked Mr. Lincoln if there was anything the he, as President, could do to help.  In his response to Jethro, Lincoln told him that he had just signed into law a decision that might help Jethro's friend.  Lincoln wrote:

"The conditions of that decision are as follows: all soldiers improperly absent from their posts, who will report at certain points designated by local recruit offices by April 1, will be restored to their regiments without punishment except for forfeiture of pay and allowances for the period of their absence." (pg 147)

Why does Jethro write a letter to Lincoln in Across Five Aprils?

Jethro decides to write a letter to Lincoln because he doesn't know what else to do - there are no clear answers to the moral dilemma that he faces.  Eb Carron has deserted from the Army and is in desperate straits; Eb regrets his action and wants only to return to his regiment, but knows he will face the ultimate punishment for desertion if he goes back.  Eb is "a lost and frightened boy, and there (is) nowhere else to go"; in despair, he had told Jethro, "you ner no one else kin help me now - not even Ol' Abe hisself".

Jethro is only eleven years old and does not know how to help Eb.  He considers seeking the advice of his father or one of the other adults in his life, but he realizes that in this difficult situation, "there ain't an answer that's any plainer to an old man than it is to me".  Eb's comment makes him think about Mr. Lincoln, "him who is highest in this land", and although Jethro knows that the law is already clear on this matter, he also reasons that the President, having himself "plowed fields in Illinois", is a good man, the kind "who looked at problems from all sides", and is not the type to easily say, "everything on this side of the line is right, and everything on the other side is wrong".  It is inarguably "a frightening thing to do, but if one did nothing - well, that was frightening too".  Jethro takes a chance, and, putting his trust in Mr. Lincoln, writes to him explaining Eb's situation and asking him what to do (Chapter 9).