What's happening to the american merchant marines between 1939-1942?

What are they doing? Especially after the lend-Lease act. Did any get into sea battles? I assume some probably died before America officially entered the war. where they memorialized properly?

The most I have heard about them is here https://www.smithsonianmag.com/history/merchant-marine-were-unsung-heroes-world-war-ii-180959253/ but I would love more information