Joseph's children

My father's father Joseph came from Poland. Soon he changed his and the family's surname to Bond, divorced his wife and went to California, leaving seven young children behind in Boston. From those three aunts and three uncles, I have three first-cousins. And I have a sister.  I have this idea that Joseph sired more children, that I have half-aunts and half-uncles and half-cousins. I have this idea that sometime, somewhere I will learn about them.