The main purpose of this legislation is to allow more shareholders in S corporations, which are a type of small business corporation that meets specific Internal Revenue Code requirements. The goal is to increase the number of eligible shareholders from 100 to 250. This change aims to help small businesses grow by allowing them to attract more investors while still benefiting from the tax advantages that S corporations enjoy. The key provision of this legislation is the amendment to the Internal Revenue Code, specifically changing the limit on the number of shareholders in an S corporation.