Page for posts of 1 category

I want to have a page for all posts within one category. I have managed to exclude the post from that category from my main blog but I cannot seem to get these posts to appear on my new page.

I am using this code in my page template:

<?php if (have_posts()) : ?>
<?php while (have_posts()) : the_post(); ?>
<?php if ( in_category(2) ) : ?>
etc….

Any idaes?