According to research data from Counterpoint's Market Monitor, Q1 2014 was the biggest quarter for smartphones in the US market reaching 33 million units (shipped, not sold) which represent a staggering 87% of the total handset shipments during that period. 

There's a ton of interesting data that's been already highlighted in Counterpoint's summary, here's some it:

  • Apple iPhone remains the top smartphone in the US, while Samsung takes the lead if you count both feature phones and smartphones.
  • Apple and Samsung together account for over two-thirds of the smartphone market. If you look at the graph above, you'll notice Samsung is trailing not too far behind Apple, even though the latter only ships 2-3 phone models at any given time.
  • Android smartphones account for 59% of the smartphones shipped during Q1/2014.
  • Windows Phone's share grew quarter on quarter but still represents less than 4% of the smartphones shipped in the US.
  • Over 75% of the smartphones shipped were LTE-capable, of which a majority (over 70%) came from Apple or Samsung.
  • Apple's iPhone captured more than half of Verizon's and AT&T smartphone shipments.
  • Samsung was the top selling brand at T-Mobile.

Counterpoint's research also indicates that T-Mobile has overtaken Sprint to become the third largest smartphone carrier, trailing closely AT&T, and showing success of the company's Uncarrier strategy.