USA. ROMA, TX. Migrants embrace after crossing a short stretch of the Rio Grande River from Mexico into the United States. The culmination of a treacherous journey that often takes 4-6 weeks. There has been a massive influx in migrants coming to the United States in 2021. Though there is an annual surge of migrants in the springtime, this year has seen the largest number in at least 15 years — more than 172,000 in March, including at least 18,700 unaccompanied children and teenagers, according to data from U.S. Customs and Border Protection.