#!/usr/bin/perl
use strict;
use warnings;

my %countries;
open my $IN, '<:encoding(utf-8)', '1.csv' or die $!;
while (<$IN>) {
    my @columns = split /;/;
    push @{ $countries{$columns[0]} }, $_;
}

for my $country (keys %countries) {
    open my $OUT, '>:encoding(utf-8)', "$country.csv" or die $!;
    for (@{ $countries{$country} }) {
        print {$OUT} $_;
    }
    close $OUT or die $!;
}