Simplify the following text for a Grade 3 native English-speaking person.
Original: Australia 's first railway was built to connect Goolwa to Port Elliot and later extended to Victor Harbor , allowing goods to move from river boats to sea boats , so that neither had to negotiate the Murray Mouth . The spread of railways to inland Australia put an end to the river trade and Goolwa 's importance as a port .
Simplified: Goolwa is an old port on the Murray River .