The main purpose of this legislation is to amend the Internal Revenue Code to allow more shareholders in S corporations. Specifically, it aims to increase the maximum number of eligible shareholders from 100 to 250. This change is intended to make it easier for small businesses to grow and attract investment by expanding their ownership base. The key provision of this legislation is the amendment to the existing law that governs S corporations. By changing the limit on the number of shareholders, it allows these corporations to have a larger pool of investors.