mend one's fences - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Improve poor relations; placate personal, political, or business contacts. For example, The senator always goes home weekends and spends time mending his fences. This metaphoric expression dates from an 1879 speech by Senator John Sherman in Mansfield, Ohio, to which he said he had returned “to look after my fences.” Although he may have meant literally to repair the fences around his farm there, media accounts of the speech took him to mean campaigning among his constituents. In succeeding decades the term was applied to nonpolitical affairs as well.