In the donner party, what was the effect of the donner party not moving ahead to fort laramie

The effect of the Donner party is they stopped at a better location with grazing for cattle and shops for wagon repairs. They planned on going fort Laramie but decided to stop at fort Bernard instead which is 10 miles east of fort Laramie because they were warned that Indians were fighting ahead the grazing for cattle was poor at for Laramie and they could get wagon repairs at fort Bernard.  

The meaning of the word in this sentence is unneeded