Taken from The Night That Unites Passover Haggadah
Rabbi Aaron Goldscheider
Why do we break the matzah in half to start the Seder? Rabbi Joseph Soloveitchik suggested that we break the matzah to emulate the ways of our ancestors in Egypt. Those who had more to eat broke their bread and shared it with others who had less. Yachatz, the act of breaking the matzah in half is a symbol of chesed, loving kindness. Even under the harshest conditions the Jew had mercy and shared his meager rations with his fellow brother and sister.