Read this article, TD to Expand in the Southeastern U.S. with Acquisition of Fir

Read this article, TD to Expand in the Southeastern U.S. with Acquisition of First Horizon, https://stories.td.com/us/en/article/td-to-expand-in-the-southeastern-u-s-with-acquisition-of-first-horizon-lang-swap and respond to this discussion question.
In under 100 words or less, explain the steps that each company needed to take preceding the announcement to the public of the merger between TD Bank and First Horizon.