The US has laws, procedures, and established institutions to ensure the peaceful transfer of power after an election.
Federal law provides presidents-elect with resources to help prepare for a new presidential administration. In fact, transition planning starts even before Election Day when the United States General Services Administration (GSA) works with both major party candidates to prepare for a potential transition of power.
To help candidates prepare for office, the government provides incoming presidents and their staff with security briefings, clearance, and office space. GSA also prepares orientation and briefing materials for key potential presidential appointees. Presidential transition offices are subject to ethics and records retention rules.
The transition process concludes on Inauguration Day when GSA orchestrates the transfer of families in the White House when an outgoing President’s personal belongings are moved out and the new President’s belongings moved in.