Why does the family have a celebration on the island?

In The Swiss Family Robinson, the Robinson family has a feast of thanksgiving on the island as a way to celebrate the fact that they have managed to survive on the island for an entire year.  This happens about midway through the book, in Chapters 22 and 23.

Delegates: representatives who cast votes at a political party's national convention. binding: if a primary or caucus is “binding” that means the delegates won in that contest are legally bound to vote for a particular candidate at the parties national convention.a primary is a preliminary election used to determine a party's nominee for a specific office. the winner of the party's caucus, or primary, wins the party nomination for that state. then the delegates meet at their party's national party convention, which is a formal gathering of all party delegates from all states.