Drawing on an unpublished collection of letters written in the wake of a terrorist attack that targeted the Palace of Versailles in 1978, this article analyzes the social reactions and practices of solidarity following this type of event. Complementing existing research that tends to focus on more recent terrorist attacks, this article demonstrates the interest of socio-historical analysis to understand these responses to terrorist attacks. Beyond analyzing the content of the letters, its purpose is also to show the value of investigating the writers’ sociography and the social contexts in which the messages were composed, in order to understand what actors say and do when they write in the wake of a terrorist attack.