What is ( standardly) the official status of " Truth" and " Falsity " in propositional logic? I'm not talking about the truth values " true" / " false". 
I'm talking about the symbols that are used in propositional calculs laws such as : 
"False  OR  p is equivalent to p "  ( where "p" stands for any sentence). 
I think that " truth" and " falsity" are called " constants". 
I've already read things such as " False is the proposition that is equivalent to all antilogies". 
But that does not seem satisfying, for any antilogy is equivalent to all antilogy, so one cannot say , I believe, " the proposition that is equivalent to any antilogy". 
By the way, how did these symbols come to be introduced? What is their " history"? 
 A: I'm not sure if there is anything like an 'official' status for $\bot$ and $\top$, but personally, my favorite way to think about them is to regard $\top$ as the generalised conjunction with $0$ conjuncts, and $\bot$ as the generalised disjunction with $0$ disjuncts.
Formally:
$$\top = \bigwedge \emptyset$$
A generalized conjunction of a bunch of statements is true iff all those statements are true. So, if you have no statements at all, then trivially 'all' of those statements are true.
This also makes it clear that $\top$ says nothing at all .... which is really what any tautology is like: if I say "my shirt is red, or it is not" ... then I effectively haven't told you anything at all. Put differently yet: tautologies have no information content.
I also likewise how in Existential Graphs, a tautology is literally represented by a bit of nothingness: it is any empty spot on the sheet of Assertion. Indeed, when the whole Sheet of Assertion is empty, i.e. you stare at an empty sheet of paper, then that to me is the perfect way to represent $\top$
On the other hand:
$$\bot = \bigvee \emptyset$$
A generalized disjunction of a set of statements is true iff at least one of the statements is true. Clearly that cannot be the case if you have no statements at all.
A contradiction is the opposite of a tautology. So, if a tautology in effect says nothing at all (it is a maximally weak statement) then a contradiction ends up saying everything: thus, contradiction says that pigs fly, and that they do not fly, and that my shirt is red, and that it is not red, etc. It is the maximally strong statement ... so strong, that it can't possibly be satisfied.
By the way, we can also nicely derive that the generalised conjunction with $0$ conjuncts has to be equivalent to $\top$, and the generalised disjunction with $0$ disjuncts the $\bot$. Here's how:
As a general principle for generalized conjunctions, we clearly want that for any sets of statements $\Gamma_1$ and $\Gamma_2$:
$$\bigwedge \Gamma_1 \land \bigwedge \Gamma_2 = \bigwedge \Gamma_1 \cup \Gamma_2$$
So, if we set $\Gamma_1 = \{ \top \}$ and $\Gamma_2  = \emptyset$, we get:
$$\bigwedge \{ \top \} \land \bigwedge \emptyset = \bigwedge \{ \top \} \cup \emptyset = \bigwedge \{ \top \}$$
And since:
$$\bigwedge \{ \top \} = \top$$
we thus get that:
$$\top \land \bigwedge \emptyset = \top$$
And that can only hold true if:
$$\bigwedge \emptyset = \top$$
We can do the same for generalized disjunctions:
We want:
$$\bigvee \Gamma_1 \lor \bigvee \Gamma_2 = \bigvee \Gamma_1 \cup \Gamma_2$$
So, if we set $\Gamma_1 = \{ \bot \}$ and $\Gamma_2  = \emptyset$, we get:
$$\bigvee \{ \bot \} \lor \bigvee \emptyset = \bigvee \{ \bot \} \cup \emptyset = \bigvee \{ \bot \}$$
And since:
$$\bigvee \{ \bot \} = \bot$$
we thus get that:
$$\bot \lor \bigvee \emptyset = \bot$$
And that can only hold true if:
$$\bigvee \emptyset = \bot$$
