Okay so I know the challenge wasn’t overly difficult but here are the answers anyway.
The order in which the Straw Hat Crew came to be:
1 Monkey D Luffy
Obviously he is number one. He is the captain after all and he is the one who pulls the rest of the crew together.
2 Roronoa Zoro
Zoro joins the crew ‘first’ as Luffy’s first mate and swordsman. He joins after defeating a tyrant marine captain.
Luffy helps free Nami’s island from terror leaving Nami free to travel. So She joins Luffy’s crew next as their Navigator.
*She does leave the crew temporarily, rejoining after Sanji.
Luffy quickly befriended after learning that his father is Yassop, a member of Shank’s crew. Ussop joined their crew at the same time as the crew finally getting a ship, the Going Merry. Luffy gave Ussop the confidence to finally set sail.
He is the first Straw Hat not to originate from East Blue. He joins the crew after Luffy helps save the Baratie and Zeff and his cooks try to persuade Sanji to join Luffy. Sanji’s dream is to find where all the oceans meet, All Blue.
6 Tony Tony Chopper
Tony Tony Chopper then joins the crew after overcoming his fear of leaving drum island to explore the world and become a better doctor with Luffy and the rest of the crew.
7 Nico Robin
Robin’s joining was readily accepted by Luffy but the rest of the crew were hesitant. It took a while but eventually Robin was accepted as one of the crew. Her desire is to find out the world’s missing history.
The only member of the crew that was ‘forced’ to join after a group effort of stealing his underwear and leading him to the Thousand Sunny where he eventually agreed to join the crew as their shipwright.
He had a very relaxed time joining the crew after Thriller Bark. He warmed his way into the crews’ hearts by singing and playing his violin. Thus the crew finally got their musician much to Luffy’s delight.
Well there you have it, the order in which everyone joined the crew!