Question: What nationality were Sam Endicott and Terry Kath?

Context paragraphs:
Brand New Love Affair (song): "Brand New Love Affair," sometimes alternatively listed as "Brand New Love Affair (Parts I and II)", is a song written by James Pankow for the group Chicago and recorded for their album Chicago VIII.  The song peaked at #61 on the charts.  Guitarist Terry Kath sings the first half while bassist Peter Cetera sings the second half.  Keyboardist Robert Lamm played the distinctive Fender Rhodes electric piano on the song—the intro particularly showcases its lush vibrato bell-like sound.

Chicago 13: Chicago 13 is the eleventh studio album by the American band Chicago, released in 1979.  The follow-up to "Hot Streets", "Chicago 13" is often critically disfavored.  This would be the band's final release that features lead guitarist Donnie Dacus, who had followed late, founding lead guitarist, Terry Kath.  All band members would contribute to the songwriting (one of only two albums where this is the case, with the other being "Chicago VII").

Sam Endicott: Samuel Bingham "Sam" Endicott (born August 13, 1974) is an American songwriter, multi-instrumentalist, actor and director.  He is best known as the lead vocalist of the Bravery, with whom he recorded three studio albums.  He is currently the lead singer of The Mercy Beat.

Free (Chicago song): "Free" is a song written by Robert Lamm as a part of the "Travel Suite" for the rock band Chicago and recorded for their third album "Chicago III" (1971), with Terry Kath singing lead vocals.  It was the first single released from this album, and peaked at #20 on the U.S. "Billboard" Hot 100.

Chicago XI: Chicago XI is the ninth studio album (eleventh overall) by the American band Chicago, released in 1977.  The album marked the end of an era for Chicago in more ways than one.  This would be the last Chicago album to feature guitarist and founding member Terry Kath prior to his death in an accident with a gun just over four months later, and the last Chicago album to be produced by James William Guercio.

25 or 6 to 4: "25 or 6 to 4" is a song written by the American musician Robert Lamm, one of the founding members of the rock/jazz fusion band Chicago.  It was recorded in 1969 for their second album, "Chicago", with Peter Cetera on lead vocals.  The album was released in January 1970 and the song was edited and released as a single in June of that same year, climbing to number four on the U.S. "Billboard" Hot 100 chart and number seven on the UK Singles Chart.  It was the band's first song to reach the top five in the U.S.  This recording features an electric guitar solo using a wah-wah pedal by Chicago guitarist Terry Kath, and a lead vocal line in Aeolian mode.  It has been included in numerous Chicago compilation albums.

Hot Streets: Hot Streets is the tenth studio album (twelfth overall) by the American band Chicago, released in 1978.  In many ways, "Hot Streets" marked the beginning of a new era for the band, turning to disco music, a move which would be derided in retrospect.  It was also the band's first album with all-new material released since their second that didn't have a numbered title.  It was also the first album not to feature original guitarist/vocalist Terry Kath, who died from an accidental self-inflicted gunshot wound in January 1978.  He was replaced by Donnie Dacus on this album.

Terry Kath: Terry Alan Kath (January 31, 1946 – January 23, 1978) was an American musician and songwriter, best known as the original guitarist, one of the lead singers and founding members of the rock band Chicago.  He has been praised by the band for his guitar skills and Ray Charles-influenced vocal style.

Brian Karscig: Brian Joseph Karscig is a musician, songwriter, and record producer, but is mostly recognized as the co-singer/guitarist/songwriter for the American Rock and Roll Band Louis XIV signed to Atlantic Records.  He also is the singer/guitarist/songwriter of American Rock Band The Nervous Wreckords.  Karscig owns Nervous Productions, and co-owner of "The Pineapple Recording Group", and has produced records for artists such as Anya Marina (Slow and Steady Seduction: Phase II) for Chopshop/Atlantic Records, The Silent Comedy, Transfer, Les Gars, Apes of Wrath, Republic of Letters, and Subsurfer.  Aside from his songwriting with LOUIS XIV, and The Nervous Wreckords, Karscig is also known for his co-writes with Brandon Flowers of The Killers ("Thief in the Choir" and "Turn the Light On"), and Sam Endicott of The Bravery ("Send it in a Letter"), as well as Anya Marina ("Afterparty at Jimmy's) and A.J. Croce's 2013 single "Keep the Change".  Karscig is also credited with additional vocals on The Killers 2006 release "Sam's Town".  Most recently Karscig toured South America as the piano/guitar player for Brandon Flowers "Desired Effect" Tour, and also joined The Killers as 2nd guitar player for their 2016 US/Canada tour.  Although The Nervous Wreckords was Karscig's solo effort after Louis XIV, Karscig started his first solo record under his birth name Brian Karscig due out early 2017.

Wishing You Were Here: "Wishing You Were Here" is a song written by Peter Cetera for the group Chicago and recorded for their album "Chicago VII" (1974), with lead vocals by Terry Kath (uncredited on the original album package), while Cetera sang the song's bridge.  The third single released from that album, it reached #11 on the U.S. "Billboard" Hot 100, #9 on the "Cash Box" Top 100, and hit #1 on the Easy Listening chart.

Supporting paragraphs: Sam Endicott Terry Kath
Answer: American