vector push_back deletes objects

Whenever I add an object to a vector, the destructors of all the
previous objects in the vector get called. Why? It seems a push_back
would just copy the object to add to the next free slot in the vector,
and leave all the other objects alone. The only time I could see this
is if the vector needs to add more memory, but this shouldn't happen
with every push_back call.

Test app:

#include <iostream>
using namespace std;

struct Location
{
    Location();
    Location(int a, int b);
    ~Location();

    void show();

    int x;
    int y;
};

Location::Location()
{
   x = 0 ;
   y = 0 ;
}

Location::Location(int a, int b)
{
      x = a ;
      y = b ;
}

Location::~Location()
{
   cout << "*** Location " << x << " , " << y
      << " destructor called *** " << endl << endl ;
}

void Location::show()
{
   cout << "( " << x << " , " << y << " ) " ;

}

#include <iostream>
#include <vector>
using namespace std ;

int main()
{
   vector<Location> Vec; // to store route

   Location L[5] ; // Location array

   // add co-ords to Location array
   for ( int i = 0 ; i < 5 ; ++ i )
   {
      L[i].x = i ;
      L[i].y = i ;
   }

   cout << endl << "Pushing .. " << endl ;

   for ( unsigned int i = 0 ; i < 5 ; ++ i )
   {
      cout << endl << "Pushing .. " ;
      L[i].show() ;
      cout << endl ;
      cout << "Vec push back start " << endl ;
      Vec.push_back( L[i] ) ;
      cout << "Vec push back end " << endl ;
   }

   cout << endl << "Leaving prog .. " << endl << endl ;
}