Simplify the following text for a Grade 10 native English-speaking person.
Original: However , it was now clear that the Republic of Maryland could not survive as an independent state , and 18 March 1857 Maryland was annexed by Liberia , becoming known henceforth as Maryland County .
Simplified: However , it was now clear that the Republic of Maryland could not survive on its own , and 18 March 1857 Maryland was added by Liberia , and became known as Maryland County .