Rubuta ci gaba don wannan sakin layi - Macchiarini ya koma Amurka a 1928 kuma, tare da zuwan Babban Mawuyacin hali ya yi aiki daga 1929 zuwa 1935 a matsayin mai sassaƙa dutse, tare da kamfanoni da yawa na Bay Area; wasu daga cikinsu an ba da kuɗin ta hanyar Shirin Fasaha na Tarayya na Gudanar da Ci gaban Ayyuka (WPA). Yayinda yake aiki a matsayin mai sassaƙa dutse, ya yi aiki a kan ayyukan a cikin shekarun 1930 tare da masu zane-zane irin su Beniamino Bufano da Ralph Stackpole. Kamar Bufano, Stackpole, da sauran masu zane-zane na Bay Area, Macchiarini ya kasance mai aiki a gefen hagu na siyasa. A wani zanga-zangar ɗalibai a lokacin yajin aikin bakin teku na Yammacin Yammacin 1934
, jami'an 'yan sandan San Francisco sun yi masa duka.