what ? b1 b2 needs sponsor ? since when?my father mother and in laws my sister visit usa no sponsor needed , i m united states citizen also.

you walk in with bare hand explain your purpost to visid show your tie to home country to return you get visa . if you show you tie to usa ( eg sponsor letter ) rejection chances goes very very up . and once you are rejected in b1 b2 you know the consequences right ?

h1b visa requires sponsor letter not b1 ? be careful