The Brazilian government recently changed their visa rules, so that citizens of the United States, Canada, Japan and Australia no longer need a visa for stays under 90 day (some extensions are available as well).  This went into effect on June 17, 2019..  The visa can be acquired at https://www.brazilvisaonline.org  or https://brazil.vfsevisa.com/brazil/online/home/index as well as other sites and is about $40.