ALICE NEEL (1900-1984) was a born rebel. Early on in life, she escaped the strictures of her small Pennsylvanian home town which, she said, “was utterly beautiful in the spring but there was no-one to paint it.”

She had wanted to be an artist since childhood but as her family were not well off she felt obliged to take a secretarial course and studied art at night school while saving up for full-time study.

Once at art college, like many a good-looking and vivacious girl, she was soon seduced, married and pregnant. There followed many years of emotional highs and lows from an eventful love life.

The death from diphtheria of her first baby at the age of one, was followed by her middle-class bohemian husband taking their second daughter Isabetta back to his native Cuba, traumas that caused Neel’s nervous breakdown in 1931. Her next significant lover burnt over 50 of her canvases and 300 drawings.

In the1940s, while living on welfare in Spanish Harlem, she brought up her two sons from different fathers but Neel also engaged with New York’s radical political and aesthetic debates and not least in  her circle was John Rothschild, who helped her out financially and emotionally for decades.

In an era when it was rare for women to even become professional artists, she resolutely carried on painting throughout all her traumas, hardships and joys. Equally amazingly, she stubbornly persisted to work in a realist style from the mid-1930s onwards, so defying dominant modernist avant-garde aesthetics. Yet she continued to chime with successive zeitgeists through changing decades.

In the early 1930s, with an emotionally charged expressionist style, Neel’s paintings dwelled on her personal pain with depictions of pregnancy, babies and hospital wards. Futility of Effort (1930) — later reproduced by the left-wing magazine Art Front  — expresses Neel’s loss of Santillana, her first baby.

In it, a small child hangs limply from the tubular frame of a hospital bed, her tiny body and pure white dress lost in the vast emptiness of the gloomy grey canvas, whose vast expanse is only broken by one small window which faces blank blackness. There is no escaping the unbearable sorrow.

But in 1933 Neel also began her “revolutionary paintings” with depictions of social injustice, inequality and urban deprivation. Two years later she joined the Communist Party. Although the meetings drove her crazy by being too bureaucratic, she said that the ideology “affected my work quite a bit” and she remained politically active throughout the dangerous McCarthy era and beyond.

Her forte lay in working from life rather than from memory or imagination, and she found her true direction when she settled to painting portraits. Rarely accepting commissions, she mostly painted people she knew or met.

Beginning in the mid-1930s, she portrayed some of the greats of the American labour movement. Pat Whalen (1935) portrays the  Baltimore union organiser of longshore men leaning forward across a table on which sits the Daily Worker. Large fists clenched, shoulders hunched, he looks beyond the viewer in sorrow and anger, laced with a gleam of hope. The dynamic composition in which diagonals abound conveys a determined, energetic call to arms.

Soon realising that she was a natural psychologist, Neel invited friends, neighbours, and passing visitors to sit for her and, when the FBI called, she even asked them to do so. They declined.

Neel talked with her sitters while painting, so establishing empathic rapport and psychological insights. Fuller Brush Man (1965) faces the viewer frontally, sensitive hands on knees, ready to spring up from his seat. All bones under his loose-fitting suit, his mobile face is edgy with salesman’s chat, his eyes that of a survivor.

Neel never posed her sitters, because their natural postures revealed as much about them as their clothes, as did their mobile facial expressions. She conveyed these with an impressive fluidity of line, expressive touch and superb, seemingly effortless compositions.

Equally important was their typification of their eras, and overall her portraits expose the injustices and diversities of contemporary life and the changing times. Like Honore de Balzac, whom she admired hugely, she wanted to paint The Human Comedy.

She resolutely defied the dominant fashion for abstraction during the aesthetic battles of the cold war, when realism was stigmatised by association with Soviet socialist realism, and her early paintings were overly expressionist.

Leaving no room for nuanced or subtle meanings, few have the presence and multivalence of her portraits. Unpretentious, not seeking for effect, they have an integrity rare in the American art world, normally characterised by posturing and jostling for attention.

But Neel never sought art world approval, and when this did eventually come when she was in her sixties, she accepted it with amused pleasure and grace because she had never painted as a career move.

She was a brave and independent artist.