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)