In
the
18th
and
the
19th
century
the
US
____________________
grew
considerably
.
The
____________________
moved
further
and
further
west
until
it
finaly
reached
the
Pacific
Ocean
.
By
1773
there
had
been
12
British
colonies
on
the
eastern
coast
of
the
North
American
Continent
.
After
a
series
of
conflicts
the
American
Revolutionary
War
started
between
the
colonists
and
their
mother
country
in
1775
.
The
French
helped
the
Americans
to
break
away
from
Britain
,
and
even
the
Spanish
and
some
Native
Tribes
____________________
on
their
side
.
When
the
war
ended
in
1783
,
the
British
colonies
became
independent
as
the
United
States
of
America
,
and
Britain
gave
up
the
land
east
of
the
Mississippi
River
,
north
of
Florida
and
south
of
Quebec
(
which
later
became
part
of
Canada
)
.
In
1803
the
US
signed
a
treaty
to
buy
a
large
piece
of
land
west
of
the
Mississippi
from
the
French
and
in
this
way
doubled
its
size
.